2022 IEEE International Symposium
on Phased Array Systems and Technology
Revolutionary Developments in Phased Array
11–14 October 2022
Digital Abstract Book
Technical Program
Wednesday, October 12
8:00 AM - 12:10 PM Wednesday Morning Parallel Sessions
Eden Vale B
Chairs: Alfonso Farina, Leonardo SpA; Michael Brandfass, Hensoldt Sensors GmbH
8:00 AM – 19: HE-R1000 Antenna Feed System developed by Thale Alenia Space in Italy
Giuseppe Orlando (Thales Alenia Space)*; Giovanni Gasparro (Thales Alenia Space); Gianpiero Fabiani (Thales Alenia Space); Danilo Fortini (Thales Alenia Space); Raffaele Carnesecchi (Thales Alenia Space); Giulio Adone (Thales Alenia Space); Davide Landi (Thales Alenia Space)
The paper provides an overview of the dual reflector afocal imaging system fed by an active phased array for Earth Observation developed by ThalesAleniaSpace in Italy (TAS-I). In section II, an overview on X band active antennas heritage is presented with a focus on Cosmo SkyMed and Cosmo Second Generation products while in section III, HE-R1000 antenna is described, going into details of Large Unfurable Reflector Assembly (LURA), Feed Array Assembly (FAA) and their integration into SAR Antenna Subsystem (SAS).
8:20 AM – 22: A Technique for on-site Calibration of Active Phased Arrays Using Two Probes
Matteo Ciattaglia (LEONARDO)*
The first calibration of active phased arrays is usually performed in factory using Near Field facilities. In most cases, the calibration can be repeated on site using built in calibration networks, reference measurements performed during the factory tests or expensive equipment. This paper explores a calibration technique that does not need factory reference measurements and that is based on on-site measurements from two external probes.
8:40 AM – 36: Recent Advances on Wideband Wide Scanning Connected Slot Arrays
Daniele Cavallo (Delft University of Technology)*
Connected slot arrays with artificial dielectric layers (ADLs) are a type of wideband wide-scanning arrays with several favorable properties. A key advantage is the high front-to-back ratio provided by the artificial dielectric, which allows to keep the distance between the radiating slots and the ground plane lower than a tenth of the wavelength over the entire frequency band of operation. This results in low-profile array designs the can be realized with multi-layer planar printed circuit boards at microwaves and millimeter waves. Another important feature is the anisotropy of the ADLs, which yields wide scanning capability without supporting the propagation of surface waves. An overview of different array designs based on this concept is given here, together with a description of the typical design steps and the achievable performance.
9:00 AM – 37: Digitally Synthesized Antenna Test Bench for Next Generation Phased Array Systems
Antonio Ciociola (Leonardo S.p.A.)*
With the increasing digitalization of radar new test benches must be employed for antenna measurements. The conventional antenna testing approach cannot be applied to fully digital phased array antenna systems. This paper explores the new challenges regarding the testing of a digital array radar which cannot be performed using a conventional network analyzer. In this case the measurement must be performed using a couple of generator/I-Q analyzer that have to be locked to the system under test during the measurement in order to ensure phase coherence of the transmitting and receiving pulse. This paper addresses a strategy to generate an auxiliary reference in the RF domain to compensate for the phase variation over the measurement time.
9:20 AM – 108: Technology developments and R&D activities at the European Space Agency for satellite communication payloads based on active antennas and digital processors
Salvatore D’Addio (European Space Agency)*
This paper provides an overview of some of the recent technology developments and R&D activities supported by the European Space Agency for next generation satellite communication payloads based on active antennas and on-board digital processing functions. In particular, recent technology developments on active antennas for LEO, MEO and GEO missions, including HPA MMICs, are presented. An introduction to R&D activities in the area of digital signal processing and digital beamforming, as well as in signal processing techniques for MIMO satellite systems is also provided. Possible future satellite systems supporting 5G are also introduced.
9:40 AM – 158: Development of Antenna Array Technologies at ONERA
Hervé Jeuland (ONERA)*; Cedric Martel (ONERA); Sylvan Bolioli (ONERA); Aurelie Dorle (ONERA); André Barka (ONERA)
This paper presents the recent activities carried out at ONERA in the field of antenna arrays using PCB technologies. These activities cover principally wideband applications with strong integration constraints, which require very low profile antennas. Two examples of antenna array developed at ONERA are presented in the paper.
10:00AM – BREAK
10:30 AM – 42: Analysis and Experimental Validation of Direction-Finding Systems for ELINT Applications
Daniele Marcantoni (Elettronica SpA)*; Riccardo Ardoino (Elettronica SpA); Goffredo Foglia (Elettronica SpA)
The Direction Finding (DF) problem is well known in the Electronic Support Measures (ESM) and Electronic signal Intelligence (ELINT) applications domain. The capability to achieve a high accuracy estimation of the angle of arrival (AOA) can be obtained by using interferometric techniques at the expense of phase ambiguity and phase errors due to the receiver unbalances. The paper presents the design implementation and experimental results of interferometric systems with a focus on wide band applications.
10:50 AM – 50: Investigation and Mitigation of Scan Blindness for State-of-the-Art Broadband Apertures
Marc Vizcarro i Carretero (Hensoldt Sensors GmbH)*; Mario Leib (Hensoldt Sensors GmbH); Tobias Trombatore (Hensoldt Sensors GmbH); Michael Sabielny (Hensoldt Sensors GmbH)
This paper describes a scan blindness investigation and mitigation study through review and design of broadband (>4:1, RL >10 dB), wide-scan (±60°), dual-polarized (linear HV) and low-loss (<0.5 dB, >90%) active electronically scanned array (AESA) apertures suitable for military airborne applications. Two state-of-the-art broadband radiator candidates are assessed and compared: the Planar Ultrawideband Modular Antenna (PUMA) and a combined Bunny Ear / Banyan Tree Antenna (BE/BT-A). Given the constrained non-grating lobe free spacing (d > λhigh/2), scan blindness arising from parasitic current paths and cavities between array elements are shown to be critical both in terms of active impedance match and polarization purity. Upon scan blindness investigation and successful mitigation, the BE/BT-A proves to be a robust candidate against a non-optimally sampled grid. Thus, enabling low-loss and highly compact TRM/aperture integration concepts to be included in future Multi-Function RF Sensor (MFRFS) systems.
11:10 AM – 53: Design and Realization of a Highly Integrated and Scalable X-Band Tile Array
Ralf Rieger (Hensoldt Sensors GmbH)*; Thomas Mueller (Hensoldt Sensors GmbH); Alexander Mueller (Hensoldt Sensors GmbH); Markus Boeck (Hensoldt)
“Modern active antennas are often assembled with hundreds or even thousands of transmit/receive modules. Thus, large numbers of these modules along with their mechanical infrastructure form a dominating factor with regard to size, weight and especially cost of such active antennas. Concerning all these parameters a quantum leap is achieved by the evolution from brick modules used to build up plank based active antennas to tile-based arrays. Key enabler for this step is the huge progress made in the field of semiconductor technologies, especially Gallium-Nitride (GaN) and Silicon-Germanium (SiGe). The integration of all the Tx/Rx module’s RF functionalities into two multifunctional MMICs made it possible to accommodate them within the typically available area of half the wavelength squared. This paper describes the development activities towards an X-band tile array performed at HENSOLDT during the last years. This includes not only the in-house design of a suitable GaN-frontend chip and a customized SiGe-beamformer chip, but also the generation of a radiating element and an RF manifold, both integrated within the tile’s PCB.”
11:30 AM – 98: On The Relationship Between Array Lattice and the Active Element Pattern of Antenna Arrays
Giovanni Petraglia (MBDA)*; Pietro vinetti (mbda); Fabio Pascariello (mbda)
The active element pattern is very often omitted or assumed isotropic when dealing with antenna array design. This assumption inevitably leads to a paradox. This paper tries to solve the paradox showing that a strict relationship exists between the array lattice of the array and the active element pattern of the array element. Starting from application of the Power Conservation Law, it is shown that the active element pattern must change with the lattice and assuming the constant/isotropic behavior leads to unfeasible and un-realistic approximation. The relationship is demonstrated by using a full wave model of a representative array.
Eden Vale C
Chairs: Dan Culkin, Northrop Grumman Corporation; Patrick Bluem, MIT Lincoln Laboratory
8:00 AM – 4: Persistent Scatterometry from GEO using Smallsats with MIMO Beamforming
Isaac Weissman (Weissman Science & Engineering Co., LLC)*
A geostationary orbit (GEO)-based scatterometer concept is presented here that offers the capability to monitor sea state over surveillance sectors with extended persistence and over a very wide area. Despite the long ranges from GEO, the resolution on the ocean surface can be preserved by employing a configuration of spread-out small satellites (smallsats) using microwave transmitters at moderate power levels. The physical smallsats are kept to a practical number by the use of multiple-input multiple-output (MIMO) beamforming that forms a virtual aperture. As illustrated herein, practical configurations appear to be realizable. Unlike traditional spaceborne radar scatterometers, the concept permits uninterrupted surveillance of selected ocean sectors.
8:20 AM – 10: FDA-MRMO Radar Interference Suppression
Zhixia Wu (Xidian University)*; Shengqi Zhu (Xidian University); Jingwei Xu (Xidian University); Lan Lan (Xidian University); Ximin Li ( Xidian University)
“In this paper, a novel method based on FDAMRA-MIMO is proposed to suppress the mainbeam range deceptive jamming. By combining minimum redundancy
arrays (MRA) and multiple-input multiple-output (MIMO) radar, the mainlobe and sidelobe interference is suppressed separately at transmitter and receiver，respectively. Sparse array of MRA is adopted at the transmitter, and uniform linear array(ULA) is adopted at the receivier.the virtual expansion of transmitting array is realized and the number of interference can be suppressed is increased.the mainlobe interference is suppressed by the non-adaptive method in the transmit dimension and the sidelobe interference is suppressed by the Generalized sidelobe canceller(GSC)method in the receive dimension.Simulationresults demonstrate the effectiveness of the proposed method”
8:40 AM – 11: Super-Resolving Multiple Mainlobe Signals in Jamming
Manuel F Fernandez (Independent Researcher)*; Kai-Bor Yu (Self-Employed)
We present a practical, effective algorithm that uses a few (10 to 20) snapshots of uniform line array data to spatially super-resolve multiple narrowband mainlobe signals even in the presence of skirt-jammers. This is done by splitting the array into two sets of sub-apertures and beamforming the data in each set with vectors of adaptive and of fixed weights. The adaptive weights are designed to suppress interferers while preserving a signal-containing spatial-response region of interest. The fixed beams are employed to sample such spatial region and help mollify any sidelobe distortions that may be introduced by the adaptive stage. The eigenvalues of the mapping interrelating the two sets of doubly-beamformed sub-apertures provide the super-resolved spatial locations of the mainlobe signals of interest.
9:00 AM – 17: Real-Time Analysis of Clutter Environments for Radar Systems
Daniel J Hebert (Lockheed Martin ATL)*; Lisa Osadciw (Lockheed Martin RMS); Danielle Landschoot (Lockheed Martin RMS)
This paper describes a technique for estimating clutter distributions in radar echoes using the K-Distribution to ultimately support adaptive techniques in real-time training data selection in angle and range dimensions. The K-Distribution is used due to its ability to model different types of natural clutter distributions by varying its shape and scale parameters. This is accomplished by using sample estimates of non-central moments from small sets of range samples (O(100)). These moment estimates have been shown to reliably predict the K-Distribution shape and scale. If necessary, these moments can be reciprocally computed from the K-Distribution’s shape and scale. The skew-kurtosis product is the metric used to quantify variations in the clutter distribution over range for a particular azimuth and elevation angle. The non-central moments are estimated from range samples and then expanded to the skew and kurtosis central moments. The K-distribution can be defined using these moments as well as identifying major distribution shape changes in range. This is an efficient approach to support any range varying adaptive or machine learning processing that relies on training from consistent clutter returns. This paper describes the approach in detail and provides examples of this technique.
9:20 AM – 18: Enhanced Knowledge Aided Space-Time Adaptive Processing (KA-STAP) Applying the Slepian Transform
Daniel J Hebert (Lockheed Martin ATL)*; Lisa Osadciw (Lockheed Martin RMS); Nguyen Nguyen (Lockheed Martin – RMS); Dimitrius Cugini (Lockheed Martin – RMS)
Knowledge Aided High Dynamic Range Space-Time Adaptive Processing (KA-HDR-STAP) approach enhances the High Dynamic Range STAP approach that uses the Fast Slepian Transform (FST) to filter out more clutter energy than traditional STAP, Reduced Rank Eigen decomposition (RR) STAP, and KA-STAP approaches using clutter typing prior to STAP. STAP relies on samples collected across sensor elements, space, and time to estimate interference with limitations due to dynamic clutter characteristics, spectrum spreading, and limited separation between clutter and signals. KA-HDR-STAP uses a particle swarm optimizer (PSO) that optimally combines the current data source covariance with a prior data source covariance based on maximizing the signal to clutter enhancement (SCE). This paper is an extended review from Osadciw, et. all [1] to assess the performance of KA-HDR-STAP to the same clutter scenarios using the signal to clutter enhancement metric. The novelty of KA-HDR-STAP includes the process of combining the two or more covariance estimates and projecting the covariance onto Slepian basis functions. The signals sample rate and selected bandwidth define the number of orthogonal Slepian basis functions. The FST from Karnik, et. all [2] is applied in KA-HDR-STAP for a more practical implementation. This article demonstrates that KA-HDR-STAP removes more clutter with a large improvement in SCE in comparison to traditional KA-STAP approaches which include sample matrix inversion (SMI) and Eigen-decomposition while achieving signal losses below those predicted by the Reed, Mallet, and Brennon (RMB) rule.
9:40 AM – 21: A Novel Technique for Polarization-Insensitive Spatial Filtering
John N Spitzmiller (Parsons)*
This paper proposes an innovative modification to a recently published spatial-processing algorithm to effect polarization-insensitive spatial filtering for a receive-antenna array. After summarizing the recently published algorithm’s description and performance characteristics, this paper infers a modification to strongly reject electromagnetic waves originating from specific directions, regardless of the waves’ polarizations. A high-fidelity digital simulation of a practical scenario demonstrates the proposed technique’s success in simultaneously producing low total receive gains in multiple undesired emitters’ directions and maintaining high effective receive gain in a single desired emitter’s direction.
10:00 AM – BREAK
10:30 AM – 23: Transmit Sub-Apertures for Beam Broadening and Frequency Diversity
Kai-Bor Yu (Self-Employed)*; Manuel F Fernandez (Independent Researcher)
We describe a set of techniques that make use of multiple sub-apertures transmitting multiple frequency beams which can be directed to the same or different directions. These techniques provide transmit beam broadening and frequency diversity capabilities. Processing schemes involve non-coherent integration for detection and a least squares procedure for combining multiple frequency measurements for monopulse angle estimation. Performance prediction tools are developed and evaluated for various target fluctuation models. Transmit beam broadening capabilities improve radar timelines in stressing scenarios and support multi-mission applications while frequency diversity improves search and track performance for Swerling 2 targets.
10:50 AM – 24: Joint Number of Antennas Detection and AoA Estimation of a Multi-antenna Transmitter by an Unauthorized Receiver
Antonios Argyriou (University of Thessaly)*
Detecting the number of antennas from which a wireless signal has originated, as well as estimating its angle-of-arrival (AoA), are critical parameters for a plethora of applications (e.g. military fingerprinting, localization, radio-astronomy, etc.). However, a rather interesting observation is that these two problems are inter-twined since they are based on detecting the number of source signals that are present at the received signal. The Akaike information criterio (AIC), the minimum distance length (MDL), and more recently random matrix theory (RMT) have been used for detecting the number of antennas or the number of AoAs but not in a joint framework. In this work we present an algorithm for a two-step application of these non-parametric methods so that we can detect simultaneously the number of antennas and the number of AoAs for a MIMO transmitter that operates in a multipath environment. Results indicate the good performance of the proposed scheme for different multipath topologies and system configurations.
11:10 AM – 45: E-DPCA Synthesis Technique in Small Linear Array Antennas with Tapered Edge Elements
Maria Pour (The University of Alabama in Huntsville)*; Tanzeela Mitha (The University of Alabama in Huntsville); Jonathan Marquardt (The University of Alabama in Huntsville)
The side and minor lobe levels of a small, equally-spaced linear array antenna are effectively reduced without any physical displacement, by utilizing the electronically displaced phase center antenna technique (E-DPCA) in conjunction with the tapered edge elements. As opposed to conventional single-mode elements, whose phase center locations are fixed, over-moded antenna elements with the E-DPCA capability are employed to realize an electronically aperiodic array out of a seven-element, linear, periodic array. It is shown that the resultant side and minor lobe levels are reduced to about -25 dB using the proposed E-DPCA technique and tapered edge elements.
11:30 AM – 51: 2D Direction-Of-Arrival Estimation of Gun-Fired Projectile using commercial Software-Defined-Radio
Clément Campo (ISL)*; Etienne Bieber (ISL); Loïc Bernard (ISL)
This paper describes a 2D transmitter-localizing ground station based on commercial Software-Defined Radio (SDR) boards. The system is developed within research on instrumented projectiles. The computation time of transmitter localization must be reduced for future embedding, but prohibitive errors are observed during outdoors validation measurements. Further modification of the array processing is proposed to increase the system accuracy. The system shown in measurements processes four channels and exhibits precision within a few degrees for a reduced computation time.
11:50 AM – 55: Scalable STAR Array Testbed
Pierre-Francois W Wolfe (MIT Lincoln Laboratory)*; Kenneth E. Kolodziej (MIT Lincoln Laboratory)
Phased array radar systems provide efficient utilization of their link budgets by focusing antenna radiation in a particular direction. Same frequency Simultaneous Transmit and Receive (STAR), also known as In-Band Full-Duplex (IBFD), capabilities more efficiently use array resources enabling execution of multiple tasks in parallel rather than relying on time-division multiplexing (TDM). Fully digital arrays ease dynamic aperture reconfiguration enabling different subarray regions to be used for STAR by application. Additionally, focusing exclusively on digital techniques for self-interference cancellation (SIC) avoids the need for specialized radiators or analog circuitry, keeping front-end hardware relatively simple. Arrays with more integrated processing resources can reduce or eliminate the need for centralized processing, improving scalability. Of course, the particular algorithms employed, data communication, and distributed processing strategies together with hardware determine scalability. This paper discusses ongoing work in support of scalable-STAR arrays with a focus on the interconnected digital backend and a testbed used for these development efforts.
Emerson
Chairs: Ryan Stevenson, Kymeta; James Liu, Intellian
8:00 AM – 106: A 1024-Element K-band Commercial SATCOM User Terminal with a G/T of 10.2 dB/K and Two Simultaneous Beams
Gokhan Gultepe (Extreme Waves, Inc.)*; Kevin Low (Extreme Waves, Inc.); Qian Ma (Extreme Waves, Inc.); Gabriel Rebeiz (Extreme Waves, Inc.)
This paper presents a receive phased array antenna (PAA) for commercial K-band satellite communication (SATCOM) user terminals. The active planar array is built on a multilayer printed circuit board (PCB) using SiGe/CMOS beamformer modules. Each module services 2×2 dual-polarized antennas and has 8 low-noise amplifiers, 8 transmit reject filters and a 16-channel beamformer chip capable of two-beam operation. The design offers reconfigurable polarization on every beam and synthesizes clockwise or counterclockwise circularly polarized beams. It can correct the axial ratio over scan angle as the dual-polarized elements have individually controlled amplitude and phase. It achieves >20 dB cross-polar discrimination (XPD) at all scan angles, and 10.2 dB/K antenna gain-to-noise temperature (G/T) at 19.5-20.2 GHz at broadside while scanning to ±70° in all planes without grating lobes. Application areas are for LEO SATCOM or for SATCOM-on-the-move for Ka-band ground terminals.
8:20 AM – 8: Prediction of Grating Lobe Level Due to Antenna Array Element Mirroring or Sequential Rotation
Chris S Merola (Intellian Technologies)*
“Antenna arrays that use sequential rotation, feedport mirroring, or tiling across multiple modules may produce grating lobes even when the chosen element spacing should be close enough to prevent such effects. Analysis reveals that grating lobes of this type are in a different class than those caused by quantization errors of the excitation coefficients, and that mitigation requires different techniques. A formula for predicting
the location and amplitude of these grating lobes based on the individual element patterns is presented. The approach is verified using both finite and infinite array simulations of a microstrip patch array with mirrored feed locations.”
8:40 AM – 100: Modern Low-Cost Phased Array Technologies and Accompanying Fixed Satellite Service (FSS) Regulatory Requirements
Antoinette Tan (Olin College of Engineering); Whitney Q Lohmeyer (Olin College of Engineering)*
Since 2016, when the Federal Communication Commission (FCC) initiated its first Processing Round for U.S. Market Access, more than twenty distinct entities applied for authority to launch and operate fixed satellite service (FSS) satellite constellations consisting of more than 70,000 satellites. One of the fundamental challenges, from a technical, regulatory and financial perspective, of these systems is a low-cost, consumer broadband, user terminal solution that complies with today’s strict regulations. At the national level, the FCC defines requirements for satellite systems in its 47 CFR Part 25 Rules. The most pertinent of these regulations for user terminals are: power flux density (25.208), earth station gain mask requirements (25.209), off\-axis equivalent isotropically radiated power (EIRP) density envelope requirements (25.218), and requirements for Earth stations in motion (ESIMs) (25.228). These regulations were first developed with geostationary (GSO) systems in mind, and have evolved to consider the increase in number of non-geostationary (NGSO) systems and megaconstellations. At the international level, the International Telecommunications Union (ITU) sets forth power flux density (PFD) and equivalent power density (EPFD) requirements in Article 22 of the Radio Regulations (RR). This work offers an overview of modern phased array user terminal technology (namely analog, digital and hybrid beamforming techniques), today’s manufacturers of phased array technology, as well as the national and international regulations with which these devices must comply.
9:00 AM – 89: Shared Aperture Full Duplex Metasurface ESA Covering the Full K/Ka Commercial and Military Satcom Bands
Ryan Stevenson (Kymeta Corporation)*; Amin Momeni (Kymeta Corporation); Hussein Esfahlani (Kymeta Corporation); Mohammad Ranjbar Nikkah (Kymeta Corporation); Cagdas Varel (Kymeta Corporation); Steven Linn (Kymeta Corporation); Mohsen Sazegar (Kymeta Corporation)
The authors present a shared aperture, full duplex, metasurface electronically scanned array (ESA) that covers the full K/Ka commercial and military receive (17.7-21.2 GHz) and transmit (27.5-31 GHz) satellite communications bands. The design leverages diffractive and holographic metasurface technology combined with varactor diode tuning to implement the ESA. The reconfigurable antenna was manufactured using the latest advances in mini-LED flat-panel display manufacturing techniques and was experimentally characterized. With an 82 cm radial aperture, a maximum gain of 40.4dBi at receive and 40.7dBi at transmit was measured in full duplex mode. Electronically controllable polarization (linear and circular) and wide 2D scanning (15°-90° elevation and 360° azimuth) were also demonstrated, with a cosine roll-off close to theoretical limits at the receive band.
9:20 AM – 132: Millimeter-wave Transparent Phased Array Antenna Using Liquid Crystal Technology
Arshad Mehmood (ALCAN Systems GmbH)*
This paper presents world’s first transparent phased array antenna operating at millimeter-wave (mmWave) frequencies. Developed for 5G mmWave customer premise equipment (CPE) applications, the antenna employs ALCAN Systems GmbH’s patented and unique liquid-crystal technology enabling high transparency, low power consumption and 2D beam steering. The antenna is designed to cover 5G New Radio (NR) n261 frequency band (27.5 GHz to 28.35 GHz) while scanning ± 55° and ± 45° in azimuth and elevation planes, respectively. Multiple prototypes are built and tested showing excellent agreement with simulations. Measurements of the prototype antenna behind double glazing window predict calculated throughput in excess of 1 Gbps across scan at 500 m range to base station.
9:40 AM – 15: PCB-Based TRX AESA for Ka-band In-Flight Connectivity
Tomohiro Takahashi (Mitsubishi Electric Corporation)*
We developed an Active Electronically Steered Array (AESA) based on a PCB and silicon RF-IC for Ka-band In-flight-connectivity (IFC). One of the goals of the AESA for IFC is to achieve low SWaP-C (Size, Weight, Power consumption and Cost) in an array of several thousand elements. We consider the wide-angle beam steering capability as an important factor to achieve low SWaP-C, and propose an AESA that combines multiple PCBs to achieve it. This enables beam steering of up to 80 degrees in circular polarization (RHCP/LHCP) in the 3.5 GHz band. In addition, a compact PCB filter capable of 30 dB harmonic suppression between the antenna element and RF-IC is realized. We also studied the radiation characteristics of the AESA when mounted on an aircraft model, and estimated the effect of the aircraft fuselage on the radiation characteristics and the radiation level to the ground. Finally, we designed and evaluated a 1,024-element Transmitting AESA and a 256-element Receiving AESA. As a result, we obtained a beam steering angle characteristic of the Transmitting AESA with an envelope of 1.05 power of the cosine. The beamforming characteristics of the Receiving AESA were also obtained as designed. Based on the results obtained in this development, AESAs can be designed to meet various IFC system requirements by array expansion.
10:00 AM – BREAK
10:30 AM – 107: Optimization of a Multibeam Satellite-Mounted Phased Array-Fed Reflector with Power Constraints
Michael F Palvig (TICRA); Tonny Rubaek (TICRA)*
“Abstract—Excitation coefficients for a phased array feeding an offset reflector are optimized for use on a geostationary satellite. The design method is exemplified by optimizing beams for inflight internet over the Atlantic at two times during a day. All sets of excitation coefficients are optimized simultaneously with power constraints to allow all beams to share 18 watt of available RF power per feed element and 1200 watt in total. The antenna operates in the Ka downlink band and is designed at 19 GHz. The reflector projected aperture diameter is 1.7 meters corresponding to 107 wavelengths. The phased feed array consists of 198 elements.”
10:50 AM – 114: Waveguide Front-End for Wide Field of View Phased Arrays using Additive Manufacturing
Esteban Menargues (SWISSto12)*; Maria Garcia-Vigueras (INSA Rennes); Santiago Capdevila (SWISSto12)
This article presents a new type of full-metal radiating element for AESAs with wide field of view. The radiating element exploits ridge waveguides to miniaturize the waveguide down to a size that is comparable to lambda/2, but unlike other ridge waveguide elements, it does not suffer from higher-order mode excitation. The latter feature enables for the first-time high radiation efficiency (>90%) and good cross-polarization discrimination (typ. 20 dB) in a field of view of ±55°. The article presents a design example for LEO constellations and experimental characterization of the new radiating element.
11:10 AM – 140: Flat panel AESAs for SATCOM links: Design and array synthesis
Sriram Muralidharan (Analog Devices Inc.)*; Sukhjinder Deo (Analog Devices Inc.)
This paper describes the design and analysis of flat panel AESAs (active-electronically steered array) Ku band SATCOM phased arrays. The goal of this work was three-fold: Perform link budget calculations for a Ku band SATCOM link for a GEO satellite, and calculate TX and RX system parameters in terms of EIRP and G/T. The system parameters are translated to size of the antenna array, antenna type, output power of the TX IC and Noise figure of the RX IC. Beamformer architectures are briefly compared, and recommendations are made for SATCOM applications including component selection. Finally, antenna analysis is performed which includes array synthesis and error calculations.
11:30 AM – 160: Deployable Electronically-Scanning Reflectarray (DESRa)
Moulder, William*; Maccabe, Andrew; Jeon, Sungeun; Bowen, Landen; Stromberg, Daniel; Diaz-Caez, Christian
A Deployable Electronically-Scanning Reflectarray (DESRa) for applications demanding wide-angle beam scanning on small satellites is presented. DESRa’s rigid, lightweight and thermally-stable panel design allows it to be folded and stowed for launch, and then unfolded in orbit to realize large apertures. Its FET-based reflective phase shifters require very low power consumption, minimizing impact on a small satellite’s limited power budget. DESRa’s novel unit cell design, which includes a sparse structural aluminum grid integrated within its antenna element is presented. The design is validated through testing of a 1.6m x 1.4m six-panel array, operating from 8.75-9.25 GHz.
11:50 AM – 7: Reflector and Reflectarray Architectures with Line Array Fed Parabolic Cylinder Optics
Michael Cooley (Northrop Grumman)*; Bret Yon (Northrop Grumman)
“Abstract – For long range radar sensors and communication links (e.g. satellite links), large antenna gains are required and many legacy systems use high gain reflectors with beams that are mechanically steered. However, mechanical scanning has inherent limitations and is insufficient for some radar and communication applications.
Direct Radiating phased Arrays (DRAs) can provide electronic scanning and/or multiple beams over a wide field of view (FOV) along 2 axes (i.e. azimuth and elevation). However, large DRAs are more complex and expensive than reflector antennas. Phased Array Fed Reflectors (PAFRs) offer intermediate performance by utilizing smaller (feed) arrays to provide electronic scanning over a limited FOV. One particular PAFR architecture, the line array fed parabolic cylinder (line fed PAFR), can provide extensive electronic scanning on one axis (up to approximately ±60 degrees) and limited electronic scanning (up to approximately ±10 degrees). The large single axis scan capability of this PAFR architecture is particularly useful for some applications.
In this paper, we review, compare and contrast various PAFR architectures that are relevant to both terrestrial and space-based sensor and communication applications. We then compare the RF performance of these architectures and describe key hardware design and implementation trades. We also describe Phased Array Fed Reflectarray (PAFRA) based architectures with parabolic cylinder based optics realized using planar reflectarrays. Finally, we describe a few notional PAFR and PAFRA architectures that are applicable for radar and communication applications.”
Lincoln Cambridge
Chairs: Eric Holzman, Northrop Grumman Corporation; Rajesh Paryani, Northrop Grumman Corporation
8:00 AM – 12: An Innovative 3D Metal Printed Dual Linear Polarized Dual Beam Tx/Rx Phased Array Heat Sink Antenna with Silicon RFIC Beamformers
Rudraishwarya Banerjee (San Diego State University)*
A 4×2 dual beam, wideband, dual linear polarized phased array antenna, consisting of innovatively shaped all metallic radiators with an overall cross-section of λ/2 × λ/2 and height nearly equal to λ/2 corresponding to the center frequency (9.50 GHz), working also as heat sink is preferred for X-band (8.5-11.5 GHz) applications. The peak broadside gain is varying between 14-11 dBi over the bandwidth. Peak gain varies from 12.8-12.5 dBi at 9.50 GHz as beam scans till ±50° in φ=00 plane and ±30° in φ=900 plane. The 4×2 antenna aperture is 3D metal printed, and the beamforming network, comprised of Anokiwave RFICs, is integrated with the antenna aperture. The temperature reduction of 60°C is obtained using this heat sink antenna structure, which is validated with an infrared (IR) camera. The Anokiwave RFIC (AWS-0101) used here has the capability to excite both polarizations simultaneously, thereby is creating dual beam in two different directions simultaneously in receive mode.
8:20 AM – 52: Dual-Polarized Ultra-Wideband 3-D Vivaldi Antenna Array at 2-40 GHz
Quang Nguyen (DEVCOM ARL)*; Theodore Anthony (DEVCOM ARL); Gregory Mitchell (DEVCOM ARL); Amir Zaghloul (DEVCOM ARL)
In this paper, we propose a 3D tapered aperture design, a.k.a the 3D Vivaldi, that yields dual-polarization with high cross-polarization isolation over a 20:1 bandwidth. We also discuss utilizing the 3D Vivaldi in an ultra-wideband array covering 2-40 GHz. To avoid grating lobes in the array, we explore the use of particle swarm optimization, a bio-inspired optimization technique, to create aperiodic spacings between the 3D Vivaldi elements in order to help suppress grating lobes up to 10 dB from 2-40 GHz.
8:40 AM – 74: Implementing Complementary Split Ring Resonators for Mutual Coupling Suppression in Dual Differentially-Fed Microstrip Patch Array Antenna
Kam Eucharist Kedze (Carleton University)*; Wenyu Zhou (Carleton University); Nima Javanbakht (Carleton University); George Xiao (National research council); Jafar Shaker (Communication research center); Rony Amaya (Carleton University)
A coupled complementary split ring resonator (CSRR) for mutual coupling suppression in dual differentially fed microstrip patch antenna is presented in this paper. The antenna is a 1 × 2 array of microstrip patches with a pair of CSRR placed on the ground plane to reduce the coupling between the two patches. By properly designing and adjusting coupling coefficient between the pair of CSRR, the coupled resonator can effectively suppress mutual coupling. The isolation is improved by employing a grounded single split ring resonator (SRR) that provides an alternative coupling path for space radiations. The approach significantly improves the isolation between the patches by over 10 dB and 5 dB in the E and H-planes respectively. An impedance bandwidth of 9.34-9.45 GHz with mutual coupling below -30 dB is also attained.
9:00 AM – 79: Impedance Bandwidth and Gain Improvement of Patch Array Antenna
Nima Javanbakht (Sanmina Corporation)*
In this paper, a novel method for improving the impedance bandwidth and gain of a low-cost microstrip patch array antenna is introduced. The proposed method is based on realizing annular ring patch, artificial magnetic conductors (AMCs), and complimentary split ring resonators (CSRRs). The proposed antenna array is realized on a multi-layer printed circuit board (PCB) laminate. A 100×100 and a 3×3 arrays are designed based on our proposed unit cell, and compared with the conventional microstrip patch arrays to examine the validity of our proposed approach. The center frequency was chosen as 29 GHz to accommodate current mm-wave 5G applications. The proposed antenna array is a suitable candidate for the 5/6G wireless communications, internet of things (IoT), and vehicle to vehicle (V2V) communications due to its wide band and relatively high gain.
9:20 AM – 90: Dual-Polarized Transmitarray with Independent Beam Control at Ka Band
Christos Exadaktylos (Florida International University)*; Abdul-Sattar Kaddour (Florida International University); Stavros Georgakopoulos (Florida International University)
“This paper presents a five-layer, dual-polarized transmitarray antenna (TA) with independent beam control, operating at Ka Band (29 GHz) for point to point wireless communications. The proposed 5.2×5.2 mm² unit-cell is based on three rectangular strips on the receiving and transmitting layers
for each polarization, which are connected using metalized vias. Each set of the three rectangular strips is designed to achieve a 180° phase resolution (i.e., 1-bit phase quantization) at the center frequency of our operating band. The proposed radiating element can form independent orthogonally polarized beams at the center frequency using the same radiating aperture. This TA design provides a maximum gain of 24.3 and 23.1 dBi at 0° and 20° scanning of the beam, respectively.”
9:40 AM – 111: A 14-17.2 GHz Dual-Polarized 256-Element Transmit Phased-Array with 40 dBW EIRP
Yusheng Yin (Extreme Waves)*; Gabriel Rebeiz (Extreme Waves)
“This paper presents a 256-element Ku-band dualpolarized transmit phased-array with wide operation frequency range. The array is based on 64 commercial beamformer chips in SiGe technology with 2×2 configuration. The chip has 6-bit of phase control and 25 dB gain tuning range. The 256-element phased-array operates at 13.75-17.2 GHz and has a measured EIRP of 40 dBW at Psat in circular polarized (CP) mode. The phased-array scans to +/-60° in both azimuth and elevation planes with low sidelobes, and it achieves <-25 dB cross polarization levels at all scan angles after calibration. The array also achieves a radiated coherent EIRP noise of -101.4 dBm/Hz, which together with 70 dBm of radiated EIRP, result in 111 dB of dynamic range per MHz of bandwidth. The 256-element array can also be configured as dual-beam mode in which each 128-element
sub-array can be operated independently. To our knowledge, this presents the first state-of-art wide bandwidth Ku-band transmit phased-array with applications areas in FMCW radars and lowcost common data link (CDL) communication systems.”
10:00 AM – BREAK
10:30 AM – 2: Design and Development of Microstrip Patch Antenna Using Balanced and Symmetric Composite Right/Left-Handed Transmission Line (CRLH-TL) for Multiband Applications
Bishoy Halim Elgndi (Alexandria Unversity)*
Electromagnetic waves are considered the heart of many industries from wireless communication, internet and optical data storage to imaging and displays. Progress in these technologies’ places challenging demands on material properties and therefore structured electromagnetic materials. Metamaterials are a special class of structured materials. Patterning on the sub-wavelength scale allows precise engineering of their electromagnetic properties over a range going far beyond natural media. In this paper, microstrip antenna consists of radiating patch and two parasitic elements (open-loop ring resonators) to serve coupling bridges with partial ground plane and composite right / left-handed transmission line (CRLH-TL) embedded in the patch antenna. The antenna topology possesses an area 30×38×1.27 mm3.The analysis and design is simulated and optimized commercial software. The good agreement between the theoretical expectation and the simulation results is observed. Finally, the proposed optimum antenna design structure has been fabricated and the measured S-parameters, VSWR of the proposed structure can be analyzed with network analyzer to demonstrate the excellent performance and meet the requirements for multiband applications.
10:50 AM – 28: Analysis and Recovery Optimization of Sporadic Reflectarray Phase Failures Based on Array Factors
Ryan J Chaky (Penn State University)*; Sawyer Campbell (Penn State University); Pingjuan Werner (Penn State University); Douglas Werner (Penn State University)
In a given antenna array system, it is not uncommon for failures affecting either the phase or amplitude of the individual elements to occur. Much work has investigated the effect and mitigation of fabrication or tolerancing errors on the main beam gain and sidelobe level from a statistical perspective. However, there are few discussions elaborating upon similar effects for the case of more sporadic random errors likely to occur throughout the operational lifetime of an array. Further, the more recent, prominent use and application of reflectarrays merits beginning to extend these failure analysis concepts to cover such antenna systems. In this work, it is shown that a 20 x 20 element reflectarray possessing a unit cell phase range of 300 degrees can sustain a failure rate of 25% and still remain above the 3 dB loss threshold when steered to broadside. For the case of 25% failure, it is possible to recover approximately 1 dB of the mainbeam gain for losses greater than 2 dB. Additionally, in the case of more structured full-column failures, the performance begins to drop below 3 dB down in the worst case at 15% failure. Similar to individual unit cell failures, it is possible to retune the remaining working elements to regain over 1 dB of lost gain.
11:10 AM – 54: Dual-band Gain Enhancing Compact GRIN Lenses
Eric B. Whiting (The Pennsylvania State University)*; Jingwei Xu (Pennsylvania State University); Sawyer Campbell (Pennsylvania State University); Jeremy Bossard (Lockheed Martin Corp.); John Barrett (Lockheed Martin Corp.); Joshua Withrow (Lockheed Martin Corp.); James Weigner (Lockheed Martin Corp.); Douglas Werner (Penn State University); Pingjuan Werner (Penn State University)
Microwave lenses provide an effective method of improving the gain of legacy antenna systems without having to do a complete redesign. At microwave frequencies, lenses can take on several forms, but gradient index (GRIN) lenses have garnered considerable attention of late because of their broadband performance and ability to control electromagnetic radiation. While previous work explored the use of a GRIN lens to enhance gain, a new direction we investigate is the optimization of a lens that enhances gain at one band but appears invisible at a second band. In addition, considerable effort is made to reduce the overall lens size. To demonstrate the effectiveness of the approach, a ceramic GRIN lens is fabricated and demonstrates +4 dB higher gain across a 15.4% fractional bandwidth (FBW) at L-band while not interfering with the performance at a second operating band with a 12.6% FBW in C-band.
11:30 AM – 66: Vital Signs Detection based on High Resolution 3-D mmWave Radar Imaging
Yu Rong (Arizona State University)*; Isabella Lenz (Arizona State University); Daniel Bliss (Arizona State University)
In this paper, a novel low-power millimeter wave (mmWave) multiple-input multiple-output (MIMO) radar with 20 transmitters (Tx) and 20 receivers (Rx) successfully demonstrates short-range high resolution human body imaging and accurate vital signs detection, including heart rate and breathing rate estimation of multiple subjects at one time. This mmWave MIMO radar system synthesizes wide band signal with stepped-frequency-modulated-continuous-wave (SFCW). Due to the increased degrees of freedom, 3-D high resolution images of the environment can be formed. With this image precise body part locations can be obtained. The human chest is chosen from the image and isolated as the target for beamforming. Vital signs parameters are estimated from the recovered phase variation at the maximum range response after beamforming. Coherently combining spatial channels significantly enhance the vital signs detection performance compared that of using a single Tx/Rx pair (single channel). Experiment demonstration on human subjects shows that the estimated breathing rate and heart rate from the mmWave MIMO system match the ground truth from the contact sensors.
11:50 AM – 151: Noncontact Radio Frequency (RF) Induced Ultrasound in the Brain
Rebecca Laher (MIT Lincoln Laboratory)*; Alan Fenn (MIT-LL); Rob Haupt (MIT Lincoln Laboratory); David J Brigada (MIT Lincoln Laboratory); Anthony Samir (MGH/MIT Center for Ultrasound Research & Translation)
A noninvasive pulsed microwave phased array for transcranial thermoacoustic ultrasound wave generation in the brain is explored using a phantom. The microwave antenna consists of a 4-element helical monopole array transmitting at 2 GHz into a cylindrical head phantom with brain tissue equivalent material. With the microwave array transmitting in pulsed mode, the brain phantom surface is heated, and the thermally induced acoustic wave is measured with an ultrasound medical transducer. In principle, this acoustic wave can be detected and the brain tissue imaged with a noninvasive optical imaging system.
1:30 - 5:20 PM Wednesday Afternoon Parallel Sessions
Eden Vale B
Chairs: Alfonso Farina, Leonardo SpA; Michael Brandfass, Hensoldt Sensors GmbH
1:30 PM – 91: CROWN Project, towards a European Multifunction AESA System
María Luz ML Gil (Indra Sistemas)*; Michael Brandfass (Hensoldt); Sebastian Durst (Fraunhofer); Isabelle LeroyNaneix (Thales); Philippe Brouard (ONERA); Antonio Nanni (Leonardo); Ubaldo Calfa (Elettronica); Mattias Thorsell (Saab); Tomas Boman (FOI); Jacco de Wit (TNO); Mantas Sakalas (Baltic Institute of Advanced Technology); Alvaro Cubillo (Indra Sistemas); José Luis Galan de la Haba (Indra Sistemas); José Correcher Soriano (Indra Sistemas)
The project European active electronically scanned array with Combined Radar, Electronic Warfare (EW) and Communications (COMMs) functions for military applications, called CROWN, was launched in July 2021 under the European program of Preparatory Action for Defence Research (PADR) and Electromagnetic Spectrum Dominance Call. It responds to the need of designing and developing high-performance and very compact Multifunction RF systems. Multifunction systems, integrating several functions in only one single system, enable small platforms operating in the complex battlefield of high capabilities, able to adapt and react in real-time to the changing scenarios and working in collaborative way with other systems. Technological challenges are found in the development of broadband antennas, digital beam forming (DBF), smart resource management and compact transmit and receive modules. Other aspects at system level as architecture definition or modelling are also tackled within the project.
1:50 PM – 104: GESTRA – upgrading to future distributed phased array radar networks for space surveillance
Christoph Reising (Fraunhofer FHR)*; Markus Gilles (Fraunhofer FHR); Rudolf Hoffmann (Fraunhofer FHR); Steven Horstmann (Fraunhofer FHR); Stephan Schneider (FraunhoferFHR)
“More and more objects are orbiting the Earth. Especially mega-constellations lead to a big number of artificial objects in space, both active and debris. This increasing amount of space debris is becoming more and more dangerous for human spaceflight. An accurate catalogue of the debris particles orbiting the Earth enables satellites to avoid collisions. The space surveillance radar GESTRA, which was developed by Fraunhofer
FHR, is a first step to create a German catalogue of objects in space. Additional transmitter and receiver units are built to create a distributed phased array radar network to increase the detection performance and accuracy of the GESTRA systems, allowing to detect even smaller debris particles with simultaniously decreased estimation uncertainity”
2:10 PM – 75: Design of TR Module Components for Ultra-Wideband Arrays up to Ka Band and Beyond
Mantas Sakalas (Baltic Institute of Advanced Technology)*; Paulius Sakalas (Baltic Institute of Advanced Technology)
“This work presents design of key Transmit/Receive (TR) module components for ultra-wideband phased arrays. A Low Noise Amplifier (LNA), a Down-Conversion Mixer (Mixer) and an Active Balun (Balun) were designed in 0.1 μm GaAs technology for the Receive (RX) module. The Transmit (TX) module was addressed with a Power Amplifier (PA) design in 0.15 μm GaN on SiC. The circuits were optimized with emphasis to achieve the maximum degree of integration, minimum Direct Current (DC) power consumption and ultra-wide bandwidth. Furthermore, a dedicated model for each of the (RX) components was created based on the measurement results. The models were then added together to form a Computer Aided Design model of the (RX) module. By this means the performance of the RX module was simulated. Promising results were achieved with respect to the targeted design goals, demonstrating the potential for integration of the designed components into a (TR) modules for future ultra-wideband arrays.”
2:30 PM – 73: Customizable Phased Array Antenna based on Domino Tiles for Satcom Applications
Federico Boulos (German Aerospace Center (DLR))*; Ulf Johannsen (Eindhoven University of Technology (TU/e)); Stefano Caizzone (DLR)
In recent years, phased array antennas are emerging as a key solution for satellite communications (satcom) ground terminal to provide global connectivity everywhere by satellite. To satisfy the user throughput requirements, the ground terminal has to transmit/receive the satellite signal with an high directive and steerable beam able to track satellites also close to horizon. In order to do that, phased arrays with a huge amount of elements are needed, posing a challenge in terms of design, manufacturing and costs. The following paper proposes ways to cope with manufacturing and design issues of large aperture by introducing modularity into the system. A domino subarray for Ka frequency band is presented and arranged to build customizable aperture.
2:50 PM – 39: Virtual Distancing: A Beam-Steering Technique for Interference Reduction in Multibeam Antennas
Piero Angeletti (European Space Agency)*; Riccardo De Gaudenzi (European Space Agency)
“The interference reduction techniques described in the paper are based on the observation that in multibeam antennas, the beam positions determine the useful gains and unwanted interference for all co-channel users. An optimization of the beam positions which guarantees a useful gain for the wanted user while reducing the interference to the co-channel users can obtain interference reduction and overall throughput improvement. Inspired by the recent emphasis on “social distancing” to prevent virus transmission, we termed these techniques “virtual distancing”. A continuous and a quantized version of the technique are described together with implementation aspects. A simplified approach to the continuous optimization problem exploits analogies with molecular dynamics. Performance results are reported for a geostationary multi-beam satellite Ka-band study case.”
3:10 PM – 40: SWAN(TM) – CAD Tool for the Design and Analysis of Large Beam Steering Slotted Waveguide Arrays
Roberto Vincenti Gatti (University of Perugia)*
Flat profile and high performances in terms of efficiency and power handling make slotted waveguide arrays attractive for many applications, ranging from radar systems to satellite and terrestrial communication systems. Apertures with hundreds or thousands of radiating slots are needed to satisfy typical requirements on beamwidth and gain. The design and analysis of such large slotted waveguide arrays is therefore extremely burdensome, if carried out with commercial 3D full-wave software tools, because of the considerable computational effort required. SWAN(TM), a powerful CAD tool for the design and analysis of this kind of antennas, is presented in this paper. High computational efficiency, accuracy and reliability of the software are demonstrated by specific examples and by comparison between simulations and measurements.
3:30 – BREAK
4:00 PM – 41: Beam steering of vortex waves by a phased array based on the field equivalence principle
Altunkan Hizal (Aselsan Inc)*
A further ability can be added to an existing phased array (PA) to include generation and steering of noncollimated or collimated electromagnetic vortex waves (VW). The concept is based on the field equivalence principle. The near field of VW’s generated by a uniform circular array (UCA) is calculated on a tilted planar finite size reference aperture (RAP) which intercepts all the VW modes. Using the Love’s equivalence principle and the vectorial VW fields on the RAP, the VW’s are calculated in the far field. RAP is divided into small rectangular subapertures (SAP), simulating the elements of a PA. On each SAP, the VW’s fields for given RAP’s tilt angle (steering angle) are calculated. These fields are to be generated by appropriately polarized PA’s antenna elements fed by the associated transmit-receive modules. The method is also applied to VW’s tightly collimated by a paraboloidal reflector. Numerical simulations obtained verified this concept.
4:20 PM – 161: A Dual-Polarized Low-Profile Wideband Antenna Array with Wide-Scan Ability
Tutku Bakan (ASELSAN)*; Burak Alptuğ Yılmaz (ASELSAN); Çağrı Çetintepe (ASELSAN); Lale Alatan (METU)
“This paper presents a novel hybrid-fed, low profile, dual polarized antenna element for phased array applications. Proposed antenna element supports a wide scan range of ±45°, ±60° and ±75° on its E-, H- and D-planes, respectively, over a wide frequency band of 8.8-11.5 GHz with an active VSWR below 2.5:1 4for each polarization channel. The antenna features a low complexity, comprising four RO3003 layers and a set of vias which serves to mitigate higher order mode propagation for the feeds. Utilized hybrid feeding method helps to increase the isolation
between the ports, which is higher than 13 dB at broadside. Dual feed lines of the first port and an internal matching network at the
second port improve the impedance bandwidth at 50 Ω coaxial connector interfaces of the antenna. Low profile of the developed
antenna element enables conformal phased array applications.”
4:40 PM – 173: Quasi 5 foci Rotman-Turner Discrete Lens Antennas with Minimised Optical Aberrations
Giovanni Toso (European Space Agency)*
Discrete Lens Antennas guarantee several advantages including a true time delay behavior, simplified beamforming networks, large field of view, high number of radiated beams. Despite to several papers proposed on the design and applications of two-dimensional constrained lens antennas, and in particular on the Rotman–Turner lens, a rigorous study focused on the minimization of optical aberrations does not seem to be available. The main results of a general procedure for the design of two-dimensional bootlace lens antennas with a flat front profile are proposed in this paper. It will be shown that the best performance is achievable when, in addition to the three nominal focal points, two additional symmetric quasi foci are present. It will be shown also that a completely different two-dimensional discrete lens, characterized again by a flat profile and 4 focal points, presents minimized aberrations when the presence of one additional quasi focus on the lens axis is guaranteed. Interestingly, both the 3- and 4-foci lenses, when optimized, converge to the same configuration which exhibits aberrations following a Chebyshev-like behavior and guarantees quasi 5 foci.
Eden Vale C
Chairs: Bryan Teague, MIT Lincoln Laboratory; Brian Janice, MIT Lincoln Laboratory
1:00 PM – 72: Sparse Direction of Arrival Estimation using Real Acoustic Data
Berkan Kilic (Aselsan Inc.)*
“Sparse direction of arrival (DOA) estimation has become highly popular especially after the development of compressive sensing (CS) theory. For hardware and/or software efficiency, it is highly common to undersample sensor array measurements using measurement matrices, and perform the DOA estimation on the compressed sensor array data. This paper demonstrates a comparative analysis among sparse DOA estimation, Multiple Signal Classification (MUSIC) and Capon’s beamformer using a real acoustic data corpus. Although it operates on the compressed data, the sparse DOA estimation algorithm outperforms MUSIC and Capon’s beamformer when an adaptive measurement matrix is used. The findings of this study verify the feasibility of sparse DOA estimation algorithms in practical applications.”
1:50 PM – 96: Hardware-Efficient Direction of Arrival Estimation using Compressive Sensing
Alper Güngör (ASELSAN Research Center)*; Berkan Kilic (Aselsan Inc.)
Compressed sensing (CS) based direction of arrival (DOA) estimation enables high performance with reduced hardware complexity. An important aspect affecting the performance of such systems is the measurement matrix that is used to reduce the number of samplers. Recent studies have proposed designing CS-DOA specific measurement matrices. However, these studies assume that each sensor is connected to each sampler channel. Such designs reduce the number of analog-to-digital samplers while increasing the number of other analog components required for mixing the sensor outputs. In this study, we tackle the problem of hardware-efficient measurement matrix design for CS based DOA estimation. We first propose constructing a hardware-efficient measurement matrix by projecting the hardware-inefficient full-matrix onto block-diagonal matrices. We rigorously derive the necessary equations and provide analytical solution for the proposed projection operation. Next, we propose a structured random permutation of the sensors to maximize the similarity between the full-matrix and the block-diagonal matrix. We thoroughly validate our proposed approach by comparing it to previously proposed block-diagonal Gaussian random matrices under a variety of simulated settings.
2:10 PM – 109: Data-Driven Covariance Estimation
John T Rogers (Mississippi State University)*; John Ball (Mississippi State University); Ali C Gurbuz (Mississippi State University)
Array processing algorithms commonly use covariance matrices as inputs. Improved performance compared to the sample covariance matrix can be achieved using knowledge of the array configuration. We present an analysis of Convolutional Neural Network (CNN) architectures for covariance matrix estimation for a simulated Uniform Linear Array (ULA). Additionally, a novel neural network configuration is presented which demonstrates reduced error and more resilience to lower Signal-to-Noise Ratio (SNR) levels when compared to the sample covariance matrix.
2:30 PM – 124: Large Scale Adaptive Beamforming
Michael A Parker (Raytheon)*
Array antennas may be built with I/Q digital I/O for each antenna element. Technology in data convertors and digital signal processing components and packaging has advanced sufficiently such that advanced algorithms may be implemented in or adjacent to the array antenna. Digitization down to the element level dramatically increases the array data rates, but localized signal processing can significantly reduce those data rates. However, the benefits of element level digitization at or near the antenna can be achieved by implementation of the algorithms in the FPGA.
2:50 PM – 121: Adaptive Transmit Beam Pattern Design for Compressed Sensing-based Direction of Arrival Estimation
Muhammet Umut Bahçeci (Aselsan Research Center)*; Alper Güngör (Aselsan Research Center); Çağrı Çetintepe (Aselsan Research Center)
Transmitter beam pattern design has a crucial role in direction of arrival (DoA) estimation for radar/sonar applications. For a good DoA estimation performance, power amplifiers are used in saturation, and pencil beams are transmitted. In a practical operation scenario, two modes are used simultaneously to both track registered targets and scan for new targets. In the first mode, transmitter tracks targets that are known with a prior distribution. The other mode is used to scan all possible angles using narrow beams. Many beams should be transmitted to scan all angles. In this study, we propose an alternative scheme that allows both modes to be used simultaneously. The proposed scheme uses specifically tailored beams exploiting the prior information to both track targets with high localization while finding emerging targets. The proposed design is based on the reciprocity property of antennas to develop an optimization problem incorporating prior target distributions through the weighting of a target matrix. As a result, the proposed design expresses an optimization-based adaptive transmitter beam pattern design for both tracked and emerging targets. We design transmit beams under certain power limits per sensor, and our design is tested for several scenarios such as signal-to-noise ratio (SNR)s and various number of transmitted beams. For a fixed number of transmit beams, the proposed design localizes both tracked targets with prior distributions and emerging targets with higher DoA estimation performance compared to classical state-of-the-art techniques.
3:10 PM – 123: Push-Sum Protocol Based Frequency and Phase Synchronization in Distributed Phased Arrays
Mohammed Rashid (Michigan State University)*; Jeffrey A. Nanzer (Michigan State University)
“In this paper, we consider the problem of joint frequency and phase synchronization of the nodes in a distributed phased array, when the communication links between the nodes are unidirectional. We assume a signal model for each node wherein oscillator frequency and phase drift and phase jitter are included. Furthermore, we suppose that the nodes iteratively share their updated frequencies and phases via a local broadcast of their signals to reach a consensus, and thus the estimation errors are also included in the signal model. A push-sum protocol based frequency and phase consensus (PsFPC) algorithm is proposed for the array synchronization. Simulation results are included where it is shown that the performance of PsFPC improves with an increase in the number of nodes in the array, the connectivity between the nodes, and the signal to noise ratio of the received signals.”
3:30 PM – BREAK
4:00 PM – 130: Multi-target Parameter Estimation in Bistatic MIMO Radar
Yunhao Liu (Imperial College London)*; Nadeem Dar (Imperial College London); Athanassios Manikas (Imperial College London)
In this paper, novel subspace-based algorithms are proposed for estimating parameters of multiple targets in bistatic MIMO radar. The parameters of interest include delay/range, Direction of Arrival (DOA), Direction of Departure (DOD), Doppler frequency and complex fading coefficient, which is a function of the target’s bistatic Radar Cross-Section (RCS). Based on parametric bistatic pulse MIMO radar signal models, subspace-based algorithms are proposed to estimate these parameters of each target in sequential order, thus avoiding the estimates association difficulties. The performance of the proposed algorithms is evaluated using computer simulation studies.
4:20 PM – 136: A Novel Block-Weighting Algorithm for Sidelobe Suppression in the Advanced Imaging System
Guanying Sun (Northeastern University)*; Mohammad Nemati (Northeastern University); Carey Rappaport (Northeastern University)
“A novel post-processing algorithm based on block-weighting is proposed in this paper for the image enhancement in AIT imaging. A variety of simulations and experiments are conducted to evaluate the performance of the proposed algorithm. The simulation and experimental results demonstrate that the proposed algorithm is effective in suppressing sidelobes and other artifacts. This algorithm is easy to implement and computationally efficient.”
4:40 PM – 137: Phased Array Frequency-Mixed OAM Beam Synthesis and Chiral Target Discrimination
Huston, Dryver R*; Brandriss, Owen; O’Connor, Patrick; Xia, Tian
This paper presents the synthesis of structured electromagnetic beams with phase-controlled radio frequency (RF) antenna arrays. The investigation is of a structured, mixed-frequency radio beam carrying orbital angular momentum (OAM). EM beams with OAM exhibit self-healing properties in the optical realm, which is of interest for radio communications and sensing applications. Also, OAM beams interact with matter differently than nonstructured beams with the same wavelength. This system mixes a phase controlled multichannel OAM signal at at 50 MHz with a 750 MHz local oscillator and sends to a circular phased array to produce an 800 MHz beam with 50 MHz OAM content. Receiving the mixed signal with a circular array followed by demodulation recovers the 50 MHz OAM signal. Experiments show that targets with chiral features corresponding to the wavelength of the 800 MHz beam selectively scatter and reflect the beam in a way that preserves the 50 MHz OAM content and depends on handedness of the feature shapes.
5:00 PM – 169: Joint estimation of ice sheet vertical velocity and englacial layer geometry from multipass synthetic aperture radar data
Ariho, Gordon*; Paden, John; Hoffman, Andrew; Christianson, Knut; Holschuh, Nicholas D.
Ice dynamics are a major factor in sea level rise and future sea-level rise projections [1]. The vertical velocity profile of the ice is one major knowledge gap in both observations and model experiments. We propose to apply multipass differential interferometric synthetic aperture radar (DInSAR) techniques to data from the Multichannel Coherent Radar Depth Sounder (MCoRDS) to measure the vertical displacement of englacial layers. Estimation of englacial layer vertical displacement requires compensating for the spatial baseline between interferometric antenna pairs using radar trajectory information and estimates of the cross-track layer slope from direction of arrival (DOA) analysis, but airborne systems suffer from unknown spatial baseline errors. The current DInSAR algorithm assumes zero error in the array position information when inferring displacement and the direction of arrival for subsurface scatterers, which means that unincorporated baseline errors map into errors in cross-track slope and vertical velocities. Here we demonstrate a maximum likelihood estimator that jointly estimates the vertical velocity, the cross-track internal layer slope, and the unknown baseline error due to GPS and Inertial Navigation System (INS) errors.
Emerson
Chairs: Vito Mecca, MIT Lincoln Laboratory; Scott Coutts, MIT Lincoln Laboratory
1:30 PM – 143: Acoustically Actuated Magnetoelectric Antenna Arrays for VLF Radiation Enhancement
Cunzheng Dong (Northeastern University)*; Yifan He (Northeastern University); Min-Gyo Jeong (Northeastern University); William Watson (BAE Systems, Fast Labs); Mohan Sanghadasa (US Army Combat Capabilities Development Command Aviation and Missile Center); Nian-xiang Sun (Northeastern University)
Magnetoelectric (ME) antennas have recently been demonstrated as a promising solution for very low frequency (VLF) communications, for their 2-3 orders of smaller dimensions and better immunity to electrical interferences than conventional electric antennas. Antenna arrays are widely used as an effective approach to enhance radiation field intensity. In this work, a new type of ME antenna with high quality factor resonator is proposed to enhance the radiation field strength and efficiency for antenna arrays. By tunning all the driving signal for each antenna unit at the same frequency and in phase, the radiation field has been linearly increased with the number of antenna arrays. A total radiation field of 200 nT at 1m has been achieved using 12 antenna arrays, which is one order of magnitude enhancement than a single antenna unit. Furthermore, the estimation of antenna efficiency based on the theory of magnetic dipole indicates that ME antennas can potentially enhance the efficiency by a square law of the number of arrays. The demonstrated results and analysis provide the potential for taking advantage of large number of ME antenna arrays for far distance transmission in VLF communications.
1:50 PM – 67: Impact of Mutual-Coupling in HF-band Uniform Linear Receiving Arrays
Gordon J Frazer (FrazerLab Pty Ltd)*; Charlie Williams (FrazerLab Pty Ltd)
Antenna arrays typically exhibit mutual coupling between the array antenna elements. For the case of a receiving array, signals appearing on one element are coupled to adjacent array elements. A spatial plane wave signal impinging on the antenna array is no longer a precisely plane wave signal after conversion to a digital voltage representation by the antenna array receivers. Array calibration is required to remove this mutual coupling and other distorting effects. It was shown recently that the signal energy due to mutual coupling has a spatial signature related to the receiving antenna array geometry. For a large linear uniformly-spaced HF-band receiving array, as used in Over-the-Horizon Radar (OTHR), we demonstrate that understanding the connection between the mutual coupling spatial signature and the array geometry simplifies array calibration. Avoiding complicated array calibration schemes for OTHR arrays can be a major factor in array geometry selection. It also explains the excellent spatial processing performance observed in established skywave radars using uniform linear arrays.
2:10 PM – 135: Phased Array Rotating Magnet Sensing of Subsurface Conductive Material
Nicholas Hanna (University of Vermont)*; Wilson Ezequelle (UVM); Dylan Burns (University of Vermont); Tian Xia (University of Vermont); Dryver R Huston (University of Vermont)
This paper describes a Phased Array Rotating Magnet sensing-system that locates and distinguishes buried ferromagnetic and non-ferromagnetic objects. The operating principle is that primary active magnetic fields interact with ferromagnetic and non-ferromagnetic conductive materials to produce secondary fields that can be measured and interpreted. The primary ELF magnetic fields are broadcast at 240 Hz (generated by 12-pole magnets rotating at an operating speed of ~40Hz) through various media. Ferromagnetic materials produce a secondary magnetic field by induced magnetization. Conductive materials produce secondary magnetic fields with eddy currents that counter the primary field. The system uses a compact array of four electronically geared, rotating multipole neodymium magnets to project the primary shape-controlled oscillating magnetic fields. Magnetometers measure the combined primary and secondary fields at a rate of 490Hz. The data are then read into a Raspberry Pi 4 Single-Board Computer (SBC) to characterize in near real-time the composition of subterranean objects. Processed readings extracted from the counter-propagated magnetic fields are fed into a neural network, training the program to discriminate between different types of sensed materials including copper, steel, iron, aluminum, and even lead. Additionally, variations of electronically geared rotating neodymium magnets are arranged and tested to maximize subsurface penetration. It is anticipated that the method extends to detecting other buried objects with ferromagnetic or electrically conductive components, such as landmines and buried explosives. Results from laboratory experiments and a field testbed are presented. Future plans are discussed.
2:30 PM – 83: Design of a Space-Based HF Vector Sensor Antenna Array for the AERO-VISTA Mission
Alexander F Morris (MIT Lincoln Laboratory)*; Alan Fenn (MIT-LL); Erik Thompson (MIT Lincoln Laboratory); Frank Robey (MIT Lincoln Laboratory); Mark Silver (MIT Lincoln Laboratory); Alai Lopez (MIT Lincoln Laboratory); Mary Knapp (MIT Haystack Observatory); Frank D Lind (MIT); Philip Erickson (MIT Haystack Observatory)
The Auroral Emissions Radio Observer (AERO) and Vector Interferometery Space Technology using AERO (VISTA) missions are small-satellite programs funded by NASA Science Mission Directorate (SMD) for Heliophysics. These missions will use identical spacecraft to observe radio emissions in Earth’s ionosphere at low earth orbit. The primary instrument onboard each spacecraft is a Low Frequency (LF) to High Frequency (HF) radio receiver utilizing a vector sensor array antenna, which is comprised of 3 orthogonal dipole antennas and 3 orthogonal loop antennas. The vector sensor array provides both spatial and polarimetric resolution of radio sources, and these observations are expected to offer new insights into the complex dynamic processes of Earths ionosphere at high latitudes. This paper describes the design, modeling, and prototyping for the vector sensor antenna array. Simulation models and preliminary testing show that the design achieves good performance in a deployable nanosatellite form factor.
2:50 PM – 92: Wideband HF Van Atta Retrodirective Array: Study and Design
Songyi Yen (University of Colorado Boulder)*; Dejan Filipovic (University of Colorado Boulder)
An active ultra-wideband Van Atta retrodirective array for HF operation is investigated. The array is enabled by an ultra-wideband element, consisting of a TEM horn combined with a loop, allowing for instantaneous coverage of the entire 2-30 MHz HF band. The antenna fits within a 3-meter radius sphere which corresponds to ka of 0.5 and 1 at 7.95 and 15.9 MHz, respectively. For instantaneous un-tuned operation, the total efficiencies are 10% and 79% at the two frequencies, respectively. The retrodirective behavior of the array is characterized using the monostatic and bistatic radar cross section responses. Simulated validation of the RCS synthesis method applied to this array is presented giving confidence to use of the method for the further analyses presented. The quality of the retrodirective behavior of the array with different element counts as well as active enhancement of the retrodirective scattering using amplification in the Van Atta beamforming network is discussed demonstrating good potential across the entire HF band.
3:10 PM – 125: The Architecture and Design of A Radio Interferometer for Thunderstorm Studies
Frank D Lind (MIT)*; Ningyu Liu (University of New Hampshire); Joseph Dwyer (University of New Hampshire); Mark Stanley (New Mexico Tech); Eloy de Lera Acedo (Cambridge Electromagnetic Technology Ltd.); Ivan Dors (University of New Hampshire)
RIFTS (Radio Interferometer for Thunderstorm Studies) represents a novel approach to thunderstorm radio imaging. The system consists of eight broadband antenna nodes which are combined with a centralized high speed digitization system. This provides multiple giga-sample per second capture of the radio emissions from lightning on sixteen simultaneous channels. Frequency coverage by the system will be between 10 MHz and 1600 MHz with the mid-band provided by modified SKALA-2 antennas (30 to 650 MHz) which are dual polarization. Several additional antenna systems will be available to provide coverage from 10 to 70 MHz and 600 to 1600 MHz for specific experiments. The result is a broadband capability for coherent RF capture on per antenna element and polarization basis. The array system can be relocated and reconfigured to provide different frequency coverage and interferometric imaging response. A modern high speed data system with GPU processing provides for on site data acquisition, reduction, and imaging in combination with a software radio architecture focused on raw voltage capture and analysis of lightning events.
3:30 PM – BREAK
4:00 – 33: Design of a Flexible Thermally-Drawn Photonics Receive Linear Dipole Phased Array Antenna at UHF
Cara Kataria (MIT Lincoln Laboratory)*; Lauren Cantley (MIT Lincoln Laboratory); Alan Fenn (MIT-LL); Domenic Terranova (MIT Lincoln Laboratory); Sivasubramaniam Yegnanarayanan (MIT Lincoln Laboratory); Beijia Zhang (MIT Lincoln Laboratory)
The design and development of a flexible thermally-drawn UHF linear dipole receive phased array is described. The required DC bias for the array low noise amplifiers (LNAs) and other components is provided by a pair of electrically conducting wires in close proximity (3.4 mm) to the wire dipoles. To improve the input impedance match, the presence of the nearby power bus requires an offset feed design for the dipoles. Linear array simulations and reactive impedance matching at UHF (420 to 450 MHz) are described. Good performance is observed, with VSWR<3:1 for scan angles up to +/-25deg from broadside when using infinite array unit cell analysis. Small array performance is also discussed, with a more limited scan range due to edge effects.
4:20 PM – 78: A Joint Angle and Delay Detection Scheme using OFDM over Broadband Acoustic Links
Zhengnan Li (Northeastern University)*; Diego Cuji (Northeastern University); Milica Stojanovic (Northeastern University)
We address the design of a joint angle and delay detection scheme over acoustic links using orthogonal frequency division multiplexing (OFDM) modulation signals. The design focuses on the broadband nature of acoustic channels, and provides angle and delay estimates of multipath arrivals in acoustic environments. We propose two algorithms for identifying the multipath arrivals, one based on an iterative procedure, and another based on a reduced-complexity search. The proposed algorithms require no extra configuration to the current OFDM acoustic communications system and necessitate minimal if no changes in the hardware. We also include analyses regarding angular resolution and ambiguity for array design and further implementation. We demonstrate the proposed algorithms in simulation and using an over-the-air acoustic communications testbed. The results indicate excellent performance for real-time implementation.
4:40 -PM – 99: 1-D and 2-D Sub-Diffraction Focusing with Circular Arrays
Nicholas E. Russo (Florida International University)*; Constantinos Zekios (Florida International University); Stavros Georgakopoulos (Florida International University)
In this work we introduce a technique for generating sub-diffraction focus in the microwave regime using circular arrays. Namely, we prove that by appropriately exciting circular arrays, an arbitrarily small focus can be theoretically achieved. We demonstrate our findings using inter-leaved and concentric circular arrays that operate at 5 GHz, and obtain one dimensional (1-D) and 2-D circularly symmetric sub-diffraction focus, respectively. In both cases, resolutions less than a twentieth of the Rayleigh resolution are achieved. Our proposed methodology for breaking the diffraction limit in the microwave regime is expected to have significant impact on various applications, such as, remote sensing and imaging.
Lincoln Cambridge
Chairs: Mike Cooley, Northrop Grumman Corporation; Paul Simmons, Georgia Tech Research Institute
1:30 PM – 6: A 0.4 km 30 Mbps Ku-Band RF Link based on a 64-Element Transmit and Receive Phased Array Antenna
Jia-Chi Chieh (SPAWAR Systems Center Pacific)*; Everly Yeo (NIWC-PAC); Raif Farkouh (NIWC-PAC); Maxwell Kerber (NIWC-PAC); Nathan Stevens (NIWC-PAC); Randall Olsen (NIWC-PAC)
Phased array antennas are becoming more and more ubiquitous largely in part because of the provision within the 5G protocol for millimeter-wave beamforming. As silicon phased array beamforming core chips become widely available, this opens cost effective solutions for highly agile line of sight (LOS) communications links which utilize classical phased array antennas. This paper describes the development and demonstration of a 0.4 km RF link which operates in the Ku-Band (13.8 GHz), which supports up to 30 Mbps data rates. The developed system is demonstrated utilizing laboratory instruments as well as with a small form factor radio. The developed phased array antenna is able to maintain link at 0.4 km at scan angles up to ±60°, utilizing a digitally modulated signal (32-QAM) at a symbol rate of 5 Msym/s while maintaining an RMS EVM of less than 6%.
1:50 PM – 43: Ka Band Phased Array Development Platform
Qui Luu (Analog Devices), Mike Ballou (Keysight)*
The growth within the satellite communication market continues to expand rapidly with advances in technology. However, the barrier to entry is driven predominately by cost and risk. The cost for research and development, thousands of manhours required from a multidisciplinary team, and the development cost to build and validate a proof of concept can be overwhelming. Especially for those who would like to explore the application space for the first time the cost and the risk may be prohibitive. To help ease the barrier to entry into the phased array technology space for satellite communication, the Aerospace and Defense organization within Analog Devices has developed a Ka band evaluation platform. Coupled with the development platform is a collaboration with Keysight Technologies on array calibration. Phased array antenna calibration has typically been time consuming and expensive. A compact antenna range coupled with commercial test equipment provides an economical and fast solution for calibrating these antennas.
2:10 PM – 64: A Figure of Merit for Simultaneous-Multi-Beam Transmit Antenna Arrays
Anton N. Atanasov (University of Twente)*; Mark Oude Alink (University of Twente); Frank E. van Vliet (TNO Defense, Safety and Security)
We present a simple and useful figure of merit (FoM) with which to evaluate the performance of simultaneous-multi-beam (SMB) transmit (TX) antenna arrays. The FoM builds upon the power-aperture product and effective isotropic radiated power for single-beam arrays and extends it to SMB arrays. The FoM is the product of radiated power, antenna aperture efficiency and the amplifiers power added efficiency. We compute the FoM for three different two-beam TX systems to highlight their differences. This will enable systematic comparison and proper system design for modern and future multi-beam radar and communications.
2:30 PM – 76: Evaluation of a Spline-Based Parameterization Scheme for Phase-Only Antenna Pattern Synthesis
Reece J Reinke (University of Oklahoma)*; David Schvartzman (Univ. of Okla., ARRC); Feng Nai (NOAA); Tian-You Yu (University of Oklahoma); Jorge Salazar (Univ. of Okla., ARRC); Bob Palmer (Univ. of Okla., ARRC)
“Phased Array Radars (PAR) are rapidly becoming the future for weather observations. The National Oceanic and Atmospheric Administration (NOAA) has identified PARs as a promising technology for polarimetric weather radar measurements. In particular, the ability of PARs to synthesize
imaging beams with minimal sensitivity losses is becoming increasingly crucial for achieving the high-temporal resolution requirements. This paper introduces a novel phase-only beam pattern synthesis method using the Non-Uniform Rational B-Spline (NURBS) parameterization scheme. Based on a genetic algorithm optimization, it generates a phase distribution to excite the array and produce a desired beam shape. The proposed
NURBS scheme is compared to previously used Bezier parameterization scheme. An S-band, 64-element uniform linear array (ULA) PAR was constructed to evaluate the performance of the NURBS scheme. Preliminary results show that the NURBS phase parameterization scheme can be used to synthesize phase weights for real-world PARs. Multiple metrics are used to evaluate the performance of the suggested parameterization scheme, such as half-power beamwidth and peak sidelobe levels. Results suggest that the NURBS scheme performs better than the Bezier scheme for synthesizing phase-only antenna patterns. Index Terms—phased array radar, antenna pattern synthesis, weather radar, genetic algorithm, digital radar.”
2:50 PM – 110: G/T Degradation in FDD Systems Utilizing Active Phased Arrays
Matthew Cullen (FIRST RF)*; Ben Kaslon (FIRST RF); Ben Gibson (FIRST RF)
In this paper, coupling effects in frequency-division duplex (FDD) phased array systems which degrade receiver G/T are discussed. Focus is given to noise generation by the transmit system and element compression of the receive system. The removal of front-end filtering and use of wideband components is found to exacerbate these effects. It is found that G/T measurements where the receive system is isolated may be uncharacteristic of actual system performance. Measurement methods to determine impact are discussed as well as design practices to mitigate this degradation.
3:10 PM – 116: Simultaneous Phased-Array Element Testing Using Orthogonal Amplitude Modulation
Saleh Almahmoud (North Carolina State University)*; Zhangjie Hong (NC STATE UNIVERSITY); Brian Floyd (North Carolina State University)
This work introduces an orthogonal amplitude modulation (AM) technique for simultaneous measurement of phased-array elements. The approach leverages a code-modulated embedded test (CoMET) technique in which a test signal is injected to the array, on-off keying is applied to each element using the existing variable-gain amplifiers and vector interpolators, signals are combined and then squared using a power detector, correlations are demodulated from the squared response, and then amplitude and phase are estimated using an equation solver. The amplitude modulation technique can be used in systems where phase modulation is either difficult or erroneous. This paper presents the theory for AM-CoMET and demonstrates its operation using an eight-element phased array transmitter operating at 8 GHz. The extracted gain and phase from the new technique is compared with a vector network analyzer (VNA), showing that AM-CoMET extracted gain and phase are accurate to within 0.25 dB gain error and 2 phase error.
3:30 PM – BREAK
4:00 PM – 148: Mutual Coupling-Based Calibration for the Horus Digital Phased Array Radar
Caleb Fulton (Univ. of Okla., ARRC)*; Patrick Kenworthy (Univ. of Okla., ARRC); Javier Lujan (Univ. of Okla., ARRC); Skyler Garner ( Univ. of Okla., ARRC); Devin Thompson (Univ. of Okla., ARRC); Mark Yeary (University of Oklahoma)
The development of the Horus digital polarimetric phased array radar at the University of Oklahoma is providing opportunities to explore and develop a number of element-level calibration and performance enhancement techniques. As digital phased arrays provide convenient mechanisms for in-situ mutual coupling measurements, the Horus engineering team has been leveraging them to iterate and improve on previously-reported algorithms that seek to align and monitor the performance of each element. Here, these algorithms and initial performance results are summarized.
4:20 PM – 162: Array Radome Replacement in the Field without Recalibration
Eric L Holzman (Northrop Grumman)*
Most high performance, active electronic scanned array (AESA) antenna systems operate inside environmentally protective radomes. Often, AESAs are calibrated in the factory with their radomes in place. Over time, radomes become damaged from exposure to the environment and must be replaced, which may require array recalibration. We describe a means to avoid recalibration of the array, whether it be in the field or back at the factory, after radome replacement, through the use of a novel replacement radome requirement based on constraining the difference between a radome’s parallel and perpendicular polarized transmission phases. With some examples, we show how to evaluate the sensitivity of this phase difference to different characteristics of the radome. Finally, we explain how to use a waveguide simulator fixture as a radome manufacturer’s process control monitor for verifying that each radome meets the replacement radome requirement.
4:40 PM – 167: In-Situ Assessment of Array Antenna Currents for Real-Time Impedance Tuning
Charles Baylis (Baylor University)*; Adam C Goad (Baylor University); Trevor Van Hoosier (Baylor University); Austin S Egbert (Baylor University); Robert J. Marks II (Baylor University)
Impedance tuning has shown promise to maximize output power, gain, or efficiency for transmitter amplifier devices in changing frequency or array environments. Using impedance tuning in phased-array elements, however, has a significant and dynamically changing impact on the transmitted array pattern. To assess the impact of impedance tuning operations on the array pattern, this paper presents a simple method to monitor the antenna input current in real time, allowing optimizations that attempt to preserve the array pattern while achieving goals of increased power, gain, or efficiency. The real-time monitoring of current provides many advantages over traditional array calibration methods in situations where the array element chains can change significantly in magnitude and/or phase during operations.
Thursday, October 13
8:00 AM - 12:10 PM Thursday Morning Parallel Sessions
Eden Vale B
Chairs: Tim Hancock, Raytheon Technologies; James Wilson, DARPA
8:00 AM – 5: UWB Hemispherical Vivaldi and BAVA Arrays for Wide Angle Scanning
Carl Pfeiffer (Air Force Research Laboratory)*; Jeffrey Massman (Air Force Research Laboratory)
We report the first ultra-wide band (UWB) arrays on a doubly curved surface for wide angle electronic scanning. Two different prototypes are developed employing Vivaldi antennas and balanced antipodal Vivaldi antennas (BAVAs) distributed over the surface of a hemisphere. The arrays employ 52 dual-polarized elements. Unit cell simulations demonstrate a good impedance match from 2-12 GHz, and finite array simulation have a realized gain that is within 1 dB of theory. The antennas and are metal 3D printed from titanium. Measurements of the arrays will be reported at the conference.
8:20 AM – 147: Low-Power K/Q-Band Digital Phased Array Chiplet
Craig A Hornbuckle (Jariet Technologies, Inc.)*; Eric Mrozek (Jariet Technologies, Inc.); Marcel Lugthart (Jariet Technologies, Inc.); Thomas Krawczyk (Jariet Technologies, Inc.)
The DARPA Millimeter Wave Digital Arrays (MIDAS) program has developed an extremely low-power integrated circuit (IC) operating from 18 to 50 GHz for use in a tiled Active Electronically Scanned Array (AESA) implementation. Each chiplet provides thirty-two transmit and thirty-two receive channels with partial beamforming in the digital domain, supporting dual-polarized operation over sixteen antenna elements with very high dynamic range. This chiplet is designed such that multiple copies of the higher-level tile assembly may be formed into arrays of an arbitrary size through abutment. This paper will describe the architecture, implementation, and performance for this ground-breaking CMOS monolithic device. Descriptions of the key circuit blocks are included as well as the simulated performance of key sub-circuits.
8:40 AM – 157: MIDAS mmW Aperture
James McSpadden (Raytheon Technologies)*; Jason Milne (Raytheon Technologies)
Raytheon Technologies teamed with Michigan State and Teledyne Scientific present a 16-element scalable AESA building block consisting of high efficiency InP HBT power amplifiers (PAs), low noise figure InGaAs HEMT Low Noise Amplifiers (LNA) with integrated T/R switches, a high-density tile interposer containing the TA1 Digital Tile, and wideband antenna to meet the MIDAS TA2 program goals. The architectural, device, and assembly technology choices are presented with Phase 1 results.
9:00 AM – 156: MIDAS Wideband mmW Digital Tile
James McSpadden (Raytheon Technologies)*; Lawrence Kushner (Raytheon Technologies)
Raytheon Technologies teamed with Michigan State University and Teledyne Scientific present a zero-IF, mixed-signal, 32-channel millimeter-wave CMOS transceiver design developed under the DARPA/MTO MIDAS program. The architectural choices, design overview, and measured results from two generations of ASIC development are presented. As part of the MIDAS 3D T/R module, element-level digital beamforming provided by this ASIC will allow multiple simultaneous beams over a wide field of regard.
9:20 AM – 142: An 18-50 GHz RF-CMOS Transmitter Front-End for a Digital Phased Array System
Shih-Chang Hung (Michigan State University)*; Asad Ali Nawaz (Michigan State University); Matt Hodek (Michigan State University); John Albrecht (Michigan State University); Sang-Min Yoo (Michigan State University)
An ultra-wideband 18–50 GHz millimeter-wave (mm-wave) transmitter is presented. The proposed mm-wave transmitter is designed for compact size and low-power consumption, and it is suitable for an element-level digital phased array system. The fully-integrated transmitter includes buffers, cascaded baseband amplifiers with sharp roll-off, a local oscillator (LO) driver, a broadband coupled line coupler, and a stacked active mixer fabricated in a 45-nm SOI CMOS process. The cascaded Sallen-Key filters are implemented to provide sharp roll-off to remove the aliasing tones from the DACs and have moderate gain to reduce the gain required of the following mixer and PA stages. The LO driver is paired with a differential broadside coupler to generate the differential in-phase (I) and quadrature (Q) LO signals locally to ensure abrupt switching of the mixer. The phase imbalance of the I and Q LO signals can be tuned out by the tunable resistance at the isolation port of the broadside coupler. The stacked double-balanced active mixer mitigates the requirement for bulky inductors between transmitter building blocks. This allows the whole transmitter to be implemented within a limited area much smaller than the array spacing to allow area for other chip functions. The resulting transmitter has a compact chip area of 0.550.85 mm2 including pads. The prototype demonstrates a maximum 14.8-dB power gain and excellent gain flatness across the frequency range of interest.
9:40 AM – 155: Millimeter Wave Digital Arrays (MIDAS) TA2: Millimeter-Wave Scalable Unconstrained Broadband Arrays (MMW SCUBA)
Josephine Chang (Northrop Grumman Mission Systems)*; Ryan Walsh (Northrop Grumman Mission Systems); Fadi Afiouni (Northrop Grumman Mission Systems); Sean McLoughlin (Northrop Grumman Mission Systems)
The Millimeter-Wave Scalable Unconstrained Broadband Array (MMW SCUBA) system leverages cutting edge chip integration, additive manufacturing, and packaging technology to realize an 18-50 GHz, dual-polarized, scalable phased array antenna with element-level digital beamforming. We report on the demonstration and test of a 16 element free-space-to-RF prototype, as well as progress on the development of a larger 64 element array prototype build which extends integration from free-space to digits.
10:00 AM – BREAK
10:30 AM – 57: A New Phased Array Construct: Intra-element Monoliths Printed & Attached to a CircuiT board (IMPACT)
Victor C Sanchez (Jacobs Technology Inc)*
A new realization of broadband phased array is introduced. The structure consists of individual additively manufactured metallic radiating elements excited through coaxial apertures on a conventional printed circuit feed board. Metallic intra-element structures which we refer to as “monoliths”, include well-known broadband features such as a Vivaldi-like flare, tight capacitive coupling to neighboring elements, and built-in shorting posts to provide a balanced feed. The construct includes additional performance-enhancing RF features such as height-variable capacitance as well as RF-benign mechanical features which make the construct light weight, repeatable, and suitable for automated pick-and-place fabrication.
10:50 AM – 71: Demonstration of X-Band Wideband Scanning Using Hybrid Beam Steering Components
Virendra Kumar (Defence Research and Development Organisation(DRDO))*; Shreeshail . (Defence Research and Development Organisation(DRDO)); Srinivas D (Defence Research and Development Organisation(DRDO)); Pramod Kumar (Defence Research and Development Organisation(DRDO)); K SREENIVASULU (DRDO); Beenamole KS (Defence Research and Development Organisation(DRDO)); Ravi Gangwar (IIT(ISM) Dhanbad)
This paper demonstrates the use of hybrid beam steering components for wideband electronic scanning. A uni- directional multifunction monolithic microwave integrated circuit (MMIC) core chip is combined with three numbers of single pole double throw (SPDT) switches to realize bi-directional TTD units for transmit and receive operation. The realized bi-directional TTD unit is characterized by its functionality at the four-element subarray for true-time delay beam steering. The 6-bit digitally controlled phase shifters and a 6-bit true-time delay (TTD) units are used in a hybrid configuration to realize an X- band wideband 16-element linear array. The element level phase delay (limited to a maximum 360 deg) and subarray level time delay in steps of 3.125 ps (maximum delay of 197ps) is applied for the array calibration and beam steering. The radiation pattern is measured at the center operating frequency f0, and the beam is steered at f0 + 0.5 GHz to validate squint-free beam scanning. The proposed configuration with a two-stage hybrid phase/time delay demonstrates the wideband beam steering and eliminates the beam squint for wide instantaneous signal bandwidth for high- resolution imaging active phased array radars.
11:10 AM – 77: Development of Balanced TCDA for MFAs
Alexander D Johnson (BAE Systems)*; Jacob Tamasy (BAE Systems); James Fung (BAE Systems Inc); Benjamin Mcmahon (BAE Systems Inc)
Multifunctional arrays (MFAs) are widely used in RF sensing, radar, and communications applications. Advancements in packaging technologies, high data rate converters, and ultra-wideband (UWB) RF electronics have enabled the proliferation of such systems. Another key enabler of the MFA is the advent of powerful electromagnetic software that allows for the design of novel UWB array apertures. In this paper, we present a new addition to the tightly coupled dipole array (TCDA) family of UWB array apertures. The presented balanced TCDA retains higher bandwidth, lower costs, better polarization purity, and lower volumes than current aperture solutions.
11:30 AM – 118: An Ultra-Wideband Fully-Planar Inverted-L Monopole (FILM) Array
Muhammad Hamza (Florida International University)*; Constantinos L. Zekios (Florida International University); Stavros Georgakopoulos (Florida International University)
A new ultra-wideband array is introduced, called the fully-planar inverted-L monopole (FILM) array. The proposed array is the first ever reported tightly coupled monopole array (TCMA). Our FILM array provides a unique solution to realize ultra-wideband tightly coupled apertures in the W and higher millimeter wave (mmWave) bands. The unit-cell architecture of the infinite FILM array is comprised of an inverted-L shaped monopole, and a capacitively coupled via-fence. This novel design eliminates the well-known broadside null from the radiation pattern of the traditional monopole element, and pushes both the common mode and loop mode resonances out of the band. To improve the impedance bandwidth and scanning ability, a dielectric-based superstrate is also used. The proposed array is extremely low profile with a maximum thickness of 0.4λ_H . Infinite array simulations of our array demonstrate a bandwidth of 3:1 (33 GHz to 101 GHz) with VSWR<3 for a maximum scan-angle of ±45 for all principal E-, H- and D-planes.
Eden Vale C
Chairs: Mark Yeary, Oklahoma State University; Caleb Fulton, Oklahoma State University
8:00 AM – 176: Analysis and Mitigation of the Reflected Power on an S-band Planar Phased Array Antenna Transmitting in a Wet Spherical Radome
Christine PARRY (MIT Lincoln Laboratory)*; Alan Fenn (MIT-LL); Alexander F Morris (MIT Lincoln Laboratory); Henry Thomas (MIT Lincoln Laboratory)
An active S-band dual-polarized multifunction phased array radar, the Advanced Technology Demonstrator (ATD), has recently been developed for weather sensing and aircraft surveillance. The ATD is a 4-m diameter active electronically scanned array (AESA) with 4864 transmit/receive (T/R) modules was installed in a spherical radome. Simulations and a novel phased array measurement technique have been explored to assess the impact of high reflectivity from a wet radome during rain that can potentially induce voltages exceeding the transmit amplifier breakdown voltage. Simulations show that when the radome surface is wet and highly reflective due to lack of hydrophobicity, certain electronic steering angles sum to a large reflected signal focused on the array face. The measurement technique uses array elements radiating one at a time to illuminate the radome in dry and wet conditions, and uses superposition to quantify the received signal power in a reference antenna on the face of the array. This measurement technique is being used prior to high-power phased array radar operation to monitor the magnitude of reflections and help avoid element transmit amplifier failures.
8:20 AM – 25: Design of a Dual-Polarized Low Sidelobe Slotted Waveguide Antenna for C-Band Phased Array Weather Radar
Takashi Uno (Mitsubishi Electric Corporation)*; Takashi Uesaka (Mitsubishi Electric Corporation); Narihito Nakamoto (Mitsubishi Electric Corporation); Toru Fukasawa (Mitsubishi Electric Corporation); Toru Takahashi (Mitsubishi Electric Corporation); Yoshio Inasawa (Mitsubishi Electric Corporation); Takeshi Yamamoto (Mitsubishi Electric Corporation); Tomoyuki Koyanagi (Mitsubishi Electric Corporation); Ikuya Kakimoto (Mitsubishi Electric Corporation); Yoshihiko Konishi (Hiroshima Institute of Technology)
This paper presents a dual-polarized low sidelobe slotted waveguide array antenna manufactured by resin injection molding for a C-band phased array weather radar. A slotted waveguide array has high efficiency and low cross-polarization, but it is generally manufactured by metal machining process, which increases its weight and cost. To solve the problems, the developed antenna is made by manufacturing approach that combines resin injection molding and plating. The vertically-polarized (V-pol.) and horizontally-polarized (H-pol.) antennas are a single-ridged slotted waveguide array and an edge-slotted waveguide array, respectively. In this paper, we focus on the V-pol. antenna, and simulation shows that −32.5 dB sidelobe level is obtained for the array, and the bandwidth with the active reflection coefficient less than −10 dB is 3.6%.
8:40 AM – 56: Untapped Capabilities of the Advanced Technology Demonstrator at the National Severe Storms Laboratory
Sebastian Torres (University Of Oklahoma)*; Christopher Curtis (University Of Oklahoma)
The Advanced Technology Demonstrator (ATD) is located in Norman, Oklahoma and is the first full-scale, S-band, dual-polarization, active, electronically scanned phased-array radar (PAR) for weather observations. The ATD became operational in the spring of 2021 after reaching its Initial Operating Capabilities (IOC). Because the ATD IOC are somewhat limited, many untapped capabilities of the ATD will be demonstrated through a process of periodic software upgrades. Research conducted with the ATD will help determine the feasibility of PAR technology for the next generation of operational weather-surveillance radars in the US.
9:00 AM – 27: Effects of Horus Antenna Patterns on Polarimetric Weather Observations
Dusan Zrnic (NOAA/NSSL)*; David Schvartzman (Univ. of Okla., ARRC); José Díaz-Díaz (Johns Hopkins University – Applied Physics Laboratory); Bob Palmer (Univ. of Okla., ARRC); Alexander Ryzhkov (Univ. of Okla., CIWRO/NSSL)
The all-digital polarimetric Horus radar is being built by the Advanced Radar Research Center at the University of Oklahoma in collaboration with NOAA’s National Severe Storms Laboratory. The radar is destined for polarimetric observations of weather. Herein we discuss polarimetric characteristics of copolar and cross-polar patterns that are required to achieve satisfactory polarimetric measurement on weather radars. Among these are matching of the beam main lobes for the horizontal and vertical polarizations. Measurements on an 8×8 element panel of the Horus antenna are used to test the theoretical postulates.
9:20 AM – 47: UAS-Mounted FMCW Radar for Observation of Weather Events
Marshall Bruner (Colorado State University)*; Chandrasekar Venkatachalam (Colorado State University)
Frequency-modulated continuous wave (FMCW) radar has seen a significant increase in use due to its ability to operate in low-power and mobile environments suited for low peak power solid state transmitters. Though there are many current applications for the FMCW technique, the majority are focused on measuring “”hard”” targets (e.g., cars, humans, etc.) and it is not heavily used in the measurement of volume targets such as precipitation. Moreover, current FMCW radars used for volumetric measurements are generally focused on very specific use cases such as vertical profiling. This work presents DARMA, a low-power, dual-polarized, FMCW radar with a phased array antenna capable of being deployed on unmanned aircraft systems (UAS). It will be used to test the feasibility of measuring and classifying complex weather events on a mobile platform which will provide different perspectives at the lowest kilometer of precipitation volumes.
9:40 AM – 48: Cross-Polar Canceller (XPC): A Technique to Reduce Cross-Polar Pattern Contamination in Polarimetric Weather Observations
Cesar Salazar (Univ. of Okla., ARRC)*; David Schvartzman (Univ. of Okla., ARRC); Boon Leng Cheong (Univ. of Okla., ARRC); Bob Palmer (Univ. of Okla., ARRC)
“This paper proposes a novel technique to improve cross-polar isolation for polarimetric phased array antennas used for meteorological observations, referred to as cross-polar canceller (XPC). It is based on the use of canceller antenna elements transmitting a scaled version of the original waveform in the polarization where the cross-polar contamination is observed but with opposite phase. The technique involves calculating the correct number of canceller elements, their location in the array, and a scaling factor for the amplitude and phase of the selected canceller elements such that maximum cross-polar isolation is possible. It is intended for dual-polarization, fully digital, phased array radar systems. It can also be applied to sub-array architectures if amplitude and phase control is possible at the element level. Previous similar efforts illustrated the potential of this technique for the alternating transmission/reception of horizontally and vertically polarized waves. In this paper, we present progress towards using this technique for the simultaneous transmission/reception of horizontally and vertically polarized waves. Preliminary results show that this technique is capable to improve cross-polar isolation by 15 dB on average, at the cost of ∼0.32 dB loss in copolar pattern gain per canceller element used. The XPC technique is being implemented in the Horus system, an S-band, polarimetric, fully digital phased array system developed by the Advanced Radar Research Center (ARRC) at the University of Oklahoma (OU).
Index Terms—polarimetric phased array radar, cross-polarization, signal processing, weather radar, simultaneous H/V.”
10:00 AM – BREAK
10:30 AM – 59: Airborne Polarimetric Doppler Phased Array Weather Radar: Digital Twin of the Active Electronically Scanned Array
Jothiram Vivekanandan (N.C.A.R>)*; Adam Karboski (N.C.A.R.); Christtopher Burghart (National center for Atmospheric Research); Turing Eret (National center for Atmospheric Research)
A weather radar using an active electronically scanned array (AESA) enables rapid scanning of the antenna beam for Doppler and polarimetric radar observation measurements. An AESA consists of radiating elements, power amplifiers, attenuators, phase shifters, array controllers, and digital converters. This paper describes a digital twin, the AESA Simulator, which models both the AESA and weather radar returns, developed to explore and validate the optimal configuration of the APAR subsystems. Using a hybrid digital beamforming architecture, multiple, simultaneous receive beams are realized upon reception. Traditional analog beamforming will be performed along each row, while digital beamforming will be performed across the per-row outputs of the AESA. The simulator sums over a spatial grid, rather than using a prescribed antenna pattern, in order to support testing of multiple receive beams, clutter mitigation algorithms, and other developments that require accurate modeling of spatial diversity. The digital twin allowed NCAR/EOL to accelerate the timeline for engineering development of the APAR radar back end (RBE) and provides the necessary configurability to conform to the eventual AESA digital data acquisition and control interfaces as AESA and RBE development converge. Together the simulator and RBE are used to evaluate/validate the radar at the system level.
10:50 AM – 115: A Novel Portable Phased Array Radar for Meteorological Remote Sensing
Mohit Kumar (Agile RF Systems)*
“The Portable Weather Radar (PWR) demonstrates a robust radar system to substantially improve weather observation for the US Air Force (USAF). The PWR uses solid-state, distributed phased-array RF electronics, implemented as a hybrid phased array and mechanical spin, scanning system. PWR supports electronic scan in elevation and mechanical scan in azimuth to provide full hemispherical volumetric coverage for
weather surveillance. The phase-spin architecture removes a mechanical elevation gimbal to significantly decrease system costs and increase lifetime. Furthermore, the radar control the system utilizes a System on Chip (SoC) to leverage an embedded Linux platform for ease of use as well as dedicated custom FPGA logic for faultless real-time radar operations and data archiving. The radar data products are provided in a
variety of file formats for compatibility with open-source and proprietary weather forecasting software applications. PWR takes advantage of faster scan times in elevation using electronic beam scanning and simultaneously overcomes the inherent differences in the gain phase of these electronic elevations beams using precise calibration methods.”
11:10 AM – 58: Two-Way Pattern Synthesis for the Airborne Phased Array Radar (APAR)
Eric Loew (N.C.A.R.)*; Randy Haupt (Haupt Associates)
Airborne, atmospheric radars need to detect the presence of relatively weak weather echoes near the earth’s surface. In order to accomplish this, both antenna sidelobes and range-time sidelobes must be suppressed considerably. This paper focuses on antenna sidelobe suppression by means of using a genetic algorithm to optimize both the thinning of the transmit aperture and the receive taper simultaneously in order to get desirable two-way sidelobe levels.
11:30 AM – 20: Novel All-Digital Beamforming Techniques for L/S/C-Band Multi-Channel Systems Leveraging Hardened DSP on Integrated Circuits
Michael Jones (Analog Devices)*; Peter Delos (Analog Devices)
As data converter sample rates increase there is a push to quantify the feasibility of all-digital beamforming solutions in L/S/C-band and beyond. For those systems requiring multiple channels to achieve the performance required, measured data on both the individual and combined-channel transmitter and receiver performance using these new converters is warranted for system architects to derive the required system-level models. This paper discusses measured multi-channel phase noise, noise spectral density, linearity and spurious improvements when using a direct-S-band-sampled digitizer transceiver as the backbone of the design. Over-the-air all-digital beamforming is also demonstrated using the hardened DSP on these new digitizer integrated circuits.
11:50 AM – 26: A Polarimetric Antenna-Calibration Method for the Horus Radar based on E-Field Back Projection
David Schvartzman (Univ. of Okla., ARRC)*; José Díaz Díaz (Johns Hopkins University – Applied Physics Laboratory); Bob Palmer (Univ. of Okla., ARRC); Dusan Zrnic (NOAA/NSSL); Caleb Fulton (Univ. of Okla., ARRC); Jorge Salazar (Univ. of Okla., ARRC); Patrick Kenworthy (Univ. of Okla., ARRC)
Phased Array Radar (PAR) technology can provide tailored, high-quality meteorological observations and is rapidly rising as a candidate for future weather radars. To conduct precise measurements of polarimetric weather variables, it is desired that the radar transmits and receives linearly polarized horizontal (H) and vertical (V) fields through beams well matched in gain and shape at every scanning direction. These characteristics are difficult to achieve because the radiation patterns of phased array antennas inherently depend on polarization, beam shape, and gain in the intended pointing direction. Polarimetric array calibration is critical to produce symmetric and matched co-polar antenna patterns at the two polarizations. In this paper, we present a new polarimetric antenna calibration procedure for the all-digital Horus radar based on holographic back projection of electric fields. Near-field Horus measurements are back-projected onto the plane of the array to derive the co-polar magnitude and phase of the H/V fields radiated by each antenna element. Digital calibration parameters are derived from back-projected fields to compensate for excitation differences and produce uniform radiation at the plane of the array. Preliminary results show that through digital calibration based on back-projected fields, co-polar H and V beam matching can be considerably improved. This naturally improves polarimetric measurement accuracy of the Horus radar by mitigating antenna-induced biases in meteorological estimates.
Emerson
Chairs: Glenn Hopkins, Georgia Tech Research Institute; Jacob Houck, Georgia Tech Research Institute
8:00 AM – 9: Flat-Top Beam Shaped Phased Array Design Using Multi-Beam Superposition
Wilfredo Rivas-Torres (Keysight Technologies Inc.)*; Murthy Upmaka (Keysight Technologies Inc.)
Several useful techniques are in use to shape Phased Array antenna patterns with optimized side lobe ratio (SLR) and wide beamwidth. The design commences with a spoiled beam Phased Array. The beam weights for the spoiled array can be obtained without using numerical optimization techniques inside an EDA tool. The beam flattening and array thinning are accomplished directly from windowing functions. A new flat-top beam shape design procedure is proposed and validated. Various studies are performed to account for the effects of different window functions, component variability, and beam scanning including a two-way beam pattern radar application.
8:20 AM – 35: True Time Delay line RFIC for X-band Timed Array Radars
K SREENIVASULU (DRDO)*; KP Ray (Department of Electronics Engineering, Defence Institute of Advanced Technology, Girinagar, Pune); Dr. Vengada Rajan (DRDO)
“In this paper, a naval design of RFIC based 4bit
True Time Delay (TTD) line circuit at X-band (8-12GHz) is
presented for wideband Timed Array Radar application. The
designed TTD line circuit is configured using eight numbers of
transmission line structures as 100ps delay element along with
distributed switching network to offer maximum time delay of
800ps. The circuit is implemented in a compact size of 25mm2
by using bulk 65nm CMOS technology. The size of the switches
and characteristic impedance of the transmission lines are scaled
optimally for low insertion loss variation across different delay
states, while maintaining flat delay performance over a wide
bandwidth. The designed circuit simulation demonstrated input
and output return loss of better than 10dB, insertion loss of
13.5dB 1dB and group delay variation of 6ps across 4GHz
bandwidth.”
8:40 AM – 44: A Composite Off-Axis Scan Method for Active Phased Array
Avnish Kumar (Indian Institute of Science, Bengaluru)*; Debasish Ghose (Indian Institute of Science); Abhijit Bhattacharyya (DRDL Hyderabad)
Phased Array Seekers (PAS) can be used to achieve longer tracking range in all-weather endo-atmospheric interceptors intended to engage long range ballistic targets or highly menuvering aerial targets. The Digital Phase Shifters (DPS) employed in PAS lead to quantization of scan steps which leads to beam pointing errors, off-boresight range losses, or poorer angular accuracies resulting in poorer engagement efficacies. In the classical phased array scanning methods, either an On-Axis target tracking is carried out over narrowly spaced beams, or a pure Off-Axis target LOS estimation is implemented over sparsely spaced ideal beams. Both the classical methods result in lower LOS confidence, the former due to the larger beam pointing errors, and the latter due the poorer off-axis estimation accuracies. This paper proposes a new idea of composite beamforming and scanning methodology. The proposed method uses a novel composite approach of formation of closely spaced phased array beams and implementation of the off-axis DOA estimation technique. The proposed method gives better accuracy in beam pointing, and better DOA estimation. In addition, the proposed approach has mathematical tractability which will help to avoid need of extensive seeker calibration and result in better angle accuracies as well. The proposed method has been integrated with the guidance algorithm to demonstrate its effectiveness during target homing.
9:00 AM – 165: Two-Dimensional Adaptive Beamforming Based On Atomic-Norm Minimization
Zeren He (Southeast University); Shengheng Liu (Southeast University)*; Xiaolong Miao (Southeast University); Yongming Huang (Southeast University)
Adaptive beamformers usually require a great number of snapshots to update the weight vectors for large phased array antennas and the training data can easily corrupted by target signals. These challenges hinder real-time applications and significantly degrade existing methods. In this context, we propose a two-dimensional (2-D) adaptive beamforming scheme based on atomic-norm optimization. The steering matrix is first reconstructed as a vector using Kronecker product. Then, the interference covariance matrix and target direction are estimated simultaneously by formulating an atomic-norm minimizing problem. This non-convex problem is solved efficiently using alternative optimization which decomposes it into two iterative stages. The proposed beamformer is free from the influence of target signals and able to adjust pointing direction adaptively. The superiority of the proposed method over other competitive methods are verified using numerical simulations.
9:20 AM – 65: Full 3D Coverage Beamforming Phased Array with Reduced Phase Shifters and Control 2D Tunable 3 × 3 Nolen Matrix
Hanxiang Zhang (Florida State University)*; Bayaner Arigong (Florida State University)
“In this paper, a 3D beamforming phased array with
2D stacked tunable Nolen matrix is presented. The fundamental
building block – tunable Nolen matrix is proposed to relax phase
tuning range of phased shifters and reduce the complexity of
control mechanism by embedding tunable phase shifters within
Nolen matrix. For each input port excitation of proposed tunable
Nolen network, a tunable progressive phase difference within
range of 120° is obtained at its output ports, and full 360° range is
achieved by exciting all three input ports. By stacking and
cascading six 3×3 Nolen matrices, nine radiation beams in unique
cubic sector can be continuously steered on azimuth and elevation
planes, realizing full 3D beamforming function. To verify the
design concept, the network has been simulated at 5.8GHz, and
the simulation results agree well with theoretical analysis”
9:40 AM – 81: Beamformer Calibration Using Coded Correlations
Zhangjie Hong (NC STATE UNIVERSITY)*; Brian Floyd (NC STATE UNIVERSITY)
Code-modulated embedded test (CoMET) has been investigated for simultaneous testing and calibration of phased-array elements using phase-shifter modulation and a single scalar detector together with an off-line equation solver. To improve the speed and reduce the complexity of the calibration, this work presents a revised methodology relying only on correlations and eliminating equation solvers within the calibration loop. The new technique, beamformer calibration using coded correlations (BC3), operates by calibrating the phased-array’s in-phase and quadrature-phase correlations between elements. Within BC3, a first method calibrates the array’s response by using two two-dimensional (2-D) correlations. A second method further reduces the total calibration time and improves accuracy by using two one-dimensional (1-D) correlations together with an empirical model to predict gain-dependent phase variation. Also, we investigate ways to improve the speed of calibration by reducing the code length and the number of searching states per iteration. The phase and gain accuracy, calibration time, and antenna beam patterns are measured and compared using original and proposed calibration methods on an eight-element receiver at 10 GHz. The most accurate BC3 method achieves 1.4 deg. and 0.23 dB root-mean-squared (RMS) phase and gain error, 1.1 dB maximum gain error and -37.8 dB calculated residual sidelobe level (RSL) for the calibrated array, with 12X speedup compared to CoMET. The fastest BC3 method achieves 2.1 deg. and 0.27 dB root-mean-squared (RMS) phase and gain error, 1.2 dB maximum gain error and -35.3 dB RSL for the array with 33X speed up compared to CoMET.
10:00 AM – BREAK
10:30 AM – 95: A Simple Analytic Technique for the Design of Linear Apertures Generating Piece-wise Polynomial Shaped Beams
Giovanni Toso (European Space Agency)*
A simple technique for the synthesis of shaped beams defined by piecewise polynomial expressions is proposed. The technique, derived generalizing an algorithm previously introduced by Ksienski, provides a continuous linear tapering in analytical format. The technique can be used to preliminary assess the fundamental parameters of a shaped pattern i.e. the ripple within the beam, the slope at the end of the shaped region, and the sidelobe level. The obtained tapering can be used as an excellent starting point in a full wave numerical analysis where additional requirements and contributions, like the mutual coupling, can be rigorously evaluated. Several examples are presented to prove the simplicity and the effectiveness of the technique.
10:50 AM – 103: A New Class of Ultra-Wideband Beamforming Networks for sub-6 GHz Bands
Dimitrios Lialios (Florida International University)*; Constantinos Zekios (Florida International University); Stavros Georgakopoulos (Florida International University)
In this work, a novel beamforming scheme is introduced that covers the sub-6 GHz bands for both satellite and terrestrial communication systems. To achieve multi-octave performance, we adopt the concept of microwave photonics and we appropriately implement it in the microwave-millimeter waves (mmWaves) regime. Specifically, in our proposed network, the desired sub-6 GHz signals are first upconverted to a mmWave frequency band where the beamforming signal processing takes place. The resulting signals are then downconverted to their original frequency band before being fed to their corresponding antenna ports for transmission. To validate our concept, a novel analog beamformer is designed, fabricated and measured, and a virtual test-bed is designed and simulated. Based on our measured and simulated results we show that our beamforming network can support bandwidths up to 6:1, which to our knowledge are the highest reported in the literature.
11:10 AM – 163: Sidelobe Reduction and Mode-Purity Enhancement of Vortex Beams from a Programmable, Rectangular Phased Array Antenna
IAN R NEMITZ (NASA)*; Christine Chevalier (HX5, LLC); Ryan Toonen (NASA); Peter Schemmel (NASA)
Tapering the magnitude of the electric field excitation of a programmable, rectangular phased array has been employed to achieve sidelobe reduction and enhancement of mode purity in vortex beams, which carry non-zero orbital angular momentum. Far-field radiation patterns pertaining to a commercial-off-the-shelf, 256-element antenna were generated via electromagnetic simulation. The patterns were decomposed into weighted sums of Laguerre-Gaussian modes. The extracted coupling coefficients were used to gauge mode purity. In comparison to a uniform excitation of the phased array elements, our studies indicate that employing a tapering technique can result in a 10.7 dB reduction of sidelobe power and a 7.22 dB improvement in worst-case, mode-to-mode cross-talk
11:30 AM – 164: Joint Optimization of Transmitting and Multiple Receiving Beams within Overlapped Subarray Structure
Hui Zeng (National University of Defense Technology)*; Zhen Hai Xu (National University of Defense and Technology); Wei Dong (National University of Defense and Technology); Shun Ping Xiao (National University of Defense and Technology)
Overlapped subarray is an attractive structure to achieve low-cost multiple receive beams. However, satisfactory weights of overlapped subarray is hard to design, especially considering the transmit beam pattern. In this paper, a method to optimize the receiving excitation of overlapped subarrays on the basis of a given transmitting pattern is proposed. The relationship between the two-level weights and the two kinds of sidelobes is analyzed at first. Then, a squential convex programming stratagy is adapted to optimize the element-level and subarray-level weights jointly to match the pre-defined transmit beam pattern. The required multi-beam coverage region and minimal sidelobe level could be obtained after these steps. Numerical experiments are presented to verify the effectiveness of this method.
11:50 AM – 178: Large Scale Adaptive Beamforming
Michael A Parker (Raytheon)*; Michael Cervantes (Raytheon)
“Array antennas may be built with I/Q digital I/O
for each antenna element. Technology in data convertors and
digital signal processing components and packaging has
advanced sufficiently such that advanced algorithms may be
implemented in or adjacent to the array antenna. Digitization
down to the element level dramatically increases the array data
rates, but localized signal processing can significantly reduce
those data rates. However, the benefits of element level
digitization at or near the antenna can be achieved by
implementation of the algorithms in the FPGA.”
Lincoln Cambridge
Chairs: Wajih Elsallal, MITRE; Pierre Dufillie, Raytheon
8:00 AM – 46: V-band Stacked Patch Phased Array
Pierre Dufilie (Raytheon Technologies)*; Elizabeth J Kowalski (MIT LL); M. David Conway (MIT Lincoln Laboratory); David Du Russel (MIT Lincoln Laboratory); Alan Fenn (MIT-LL)
MIT Lincoln Laboratory is developing a planar V-band phased array antenna. The radiator is required to provide 15% bandwidth with 30° elevation and 50° azimuth scanning capability with vertical polarization. Due to the high level of integration of the radiator and the RF front-end, the goal for the antenna array is to be integrated on printed circuit board (PCB) technology with the T/R module mounted on the opposing side. This design results in a very tightly integrated radiator and RF distribution network in a multi-layer PCB stack up that utilizes Ormet paste technology. A detailed description of the antenna array and RF feed network will be reviewed.
8:20 AM – 69: System-Level Model for mmWave-over-Fiber Distributed Antenna Systems
Arno Moerman (Ghent University)*; Olivier Caytan (Ghent University); Laura Van Messem (Ghent University); Igor Lima de Paula (Ghent University); Joris Van Kerrebrouck (Ghent University); Guy Torfs (Ghent University); Piet Demeester (Ghent University); Hendrik Rogier (Ghent University); Sam Lemey (Ghent University)
“A mmWave-over-fiber distributed antenna system (DAS), in combination with highly efficient air-filled substrate-integrated-waveguide (AFSIW) remote antenna units (RAUs), proves to be a prime candidate to counter the harsh propagation conditions that arise at mmWave frequencies. This paper proposes a system-level model to accurately analyze the link quality of a downlink mmWave-over-fiber wireless link in a time-efficient way.
The model includes a realistic antenna description, fiber losses, and non-linear effects of the opto-electrical/electro-optical transducers and the electrical amplifiers. This gives in-depth insight into the signal quality at each stage of the link and enables offline link optimization. In addition, the modular nature allows incorporating more advanced wireless channel models/measurements which can be used to optimize RAU placement in the future. Finally, the model is validated by means of a measurement campaign, demonstrating good agreement.”
8:40 AM – 97: Experimental Evaluation of a Variable Length Beam Selection Framework in a USRP based Testbed with mmWave Frontends and Butler Matrices
Mostafa Khalili Marandi (Technische Universität Dresden)*; Shizhang Wei (Technische Universität Dresden); Behnam Khodapanah (Technische Universität Dresden); Wolfgang Rave (Technische Universität Dresden); Gerhard Fettweis (TU Dresden)
In this work, we aim to experimentally evaluate the performance of the novel variable length beam selection framework known as the Sequential Competition and Elimination Test (SCET) in a realistic mmWave link. The experimental setup employs hardware in the loop including a pair of 16×16 Butler Matrices developed at TU Dresden which provides a codebook of orthogonal beams that are connected through an electronic switch to a single RF chain. We have designed multiple measurement scenarios in which beams with different main-lobe directions are automatically probed at the TX and RX through different channel realizations. The acquired measurements are processed in Matlab to benchmark the alignment accuracy and efficiency after beam selection. The results indicate the superior performance of the variable length detection framework for beam selection. SCET is adaptive to any channel realization while achieving a better efficiency/accuracy compared to the fixed-length test. Furthermore, it is resilient in the presence of hardware impairments and non-ideal pre-beamforming frequency and time synchronization.
9:00 AM – 102: Fast Beam Alignment Via True Time Delay Frequency Dependent Beamforming Using Fixed and Variable Length Tests
Christoph Jans (TU-Dresden)*; Wolfgang Rave (TU Dresden); Gerhard Fettweis (TU Dresden)
“In this work, we present a time efficient solution to the initial beam alignment/acquisition of a hybrid beamforming millimeter wave communication system. Our proposal is based on adding a frequency dependent beamforming device at the transmitter which is capable of simultaneously testing all spatial angles and, therefore, any set of possible beamformers from an analog codebook. Such a device employed outperforms any kind of consecutive beamformer testing, e.g., exhaustive search, in terms of testing overhead and receive power loss after beamforming. To further increase the time efficiency, a variable length testing technique in combination with the frequency dependent beamformer is described, which is adaptive to any signal to noise ratio or varying channel condition. Especially in the low signal to noise ratio regime, an overall speed-up can be achieved. The described radar-like solution to the initial beam alignment problem may act as an enabler for mmWave communication in fast-varying and challenging environments.”
9:20 AM – 113: Determining the OIP3 and Bias Network Resonances of Phased-Arrays Using Far-Field Techniques
Yusheng Yin (Extreme Waves)*; Gabriel Rebeiz (Extreme Waves)
“The output 3rd-order intercept point (OIP3) is a figure of merit to evaluate the linearity of an amplifier or a system of amplifier blocks. Also, the OIP3 is a useful term to estimate the 3rd-order intermodulation (IM3) components and the adjacent channel power ratio (ACPR) of a transmitter for complex modulation measurements. A phased array operating in a transmit mode combines the output of several power amplifiers in free space, and the far-field contains an average and a scaled version of the linear and nonlinear components of the individual power amplifiers. In this paper, a method to determine the OIP3 of phased-array amplifiers using a far-field measurement is derived and verified by experiment. The far-field OIP3 is then measured using a 5G 28 GHz 32-element phased array employing 2×2 beamformer chips, and the far-field derived OIP3 agrees well
with measurements done on a single amplifier. This technique therefore allows the user to determine the (average) OIP3 of the power amplifiers used in an array even if they do not have access to the individual beamformer chip. An additional benefit is the ability of characterizing the PCB bias network resonances in a
phased-array environment.”
9:40 AM – 171: An SICL-Fed Compact Magnetoelectric Dipole Antenna for 5G Millimeter Wave Bands
Aditya Singh (Queen’s University)*; Carlos E. Saavedra (Queen’s University)
A compact magnetoelectric (ME) dipole antenna element is proposed for design of wide beam steering arrays in the 5G millimeter wave (mm-wave) bands n257, n258 and n261. The antenna employs an substrate integrated coaxial line (SICL) based feed. The SICL line is transformed into a coplanar waveguide (CPW) to enable feed for ME dipole antenna. With adoption of a U-shaped shorting strip and SICL-CPW-based feed, the element achieves an -10 dB impedance bandwidth (IBW) of 22.5% at the center frequency (f0) of 26.8 GHz. Notably, the antenna offers nearly 100 degrees of 3 dB beam width and a compact size of 0.32 wavelengths x 0.32 wavelengths at f0. Using full-wave simulations, an 8-element uniform linear array (ULA) is shown to exhibit fractional IBW of 19%, max gain > 15 dBi with large beam steering angles up to 56 degrees. The antenna can be easily fabricated using standard four layer printed circuit board (PCB) technology on Rogers 5880 dielectric laminates.
10:00 AM – BREAK
10:30 AM – 129: Wide-Angle Flattened Luneburg Lens for Millimeter-Wave Beam Steering Applications
Mohamed Elmansouri (University of Colorado Boulder)*; Dejan Filipovic (University of Colorado Boulder)
This paper discusses the design and performance of a three-dimensional (3D) Luneburg lens (LL) with a flat focal surface for wide-angle beam steering applications. The lens is designed based on the theory of quasi-conformal transformation optics (QCTO) where simple mathematical procedures are applied to flatten a portion of a spherical LL surface. Different design aspects to control the lens scan range are discussed. A wideband magneto-electric dipole antenna operating over the 24-40 GHz band is designed and used as a feed to demonstrate the lens performance. A flattened LL with beam steering capability up to ±65° is fabricated using 3D printing process and preliminary performance thereof is presented.
10:50 AM – 138: Compact Antenna Test Range EVM Measurements of a Millimeter-Wave Phased Array using a VNA
Dustin Brown (UCLA Antenna Lab)*; Yahya Rahmat-Samii
Compact antenna test ranges (CATR) are favorable for over-the-air (OTA) measurements of millimeter-wave phased arrays because they use a feed and parabolic reflector to emulate the plane wave condition of far field ranges within a significantly-reduced volume, which lowers path loss and helps compensate for the limited dynamic range of test instruments such as vector network analyzers (VNA). Error vector magnitude (EVM) is a measure of digitally-modulated signal quality that is increasingly used as a benchmark of millimeter-wave array performance, since it includes the effects of each element’s radiated power and RF integrated circuit (RFIC) linearity across the signal bandwidth. This paper presents EVM measurements of independent phased array elements within a CATR using spectrum analysis on a VNA receiver, performed at Keysight in Santa Rosa, CA, USA.
1:30 - 5:20 PM Thursday Afternoon Parallel Sessions
Eden Vale B
Chairs: Mark Fosberry, MITRE; Orin Henry, Georgia Tech Research Institute
1:30 PM – 128: A Wide-Angle Scanning Phased Array Antenna with Non-Reciprocal Butler Matrix Beamforming Network
Hamed Tadayon (INRS); Mansoor Dashti Ardakani (INRS University)*; Reza Karimian (The George Washington University); Shahrokh Ahmadi (The George Washington UThe theory and design of a wide scan array antenna is presented in this paper. A conventional 4×4 butler matrix is used to achieve four fundamental beam arrays from -45 degrees to +45 degrees. The use of Butler Matrix relaxes the requirement of the progressive phase and consequently the phase shifters to a good degree. The butler matrix is also integrated into a non-reciprocal feed network structure to achieve a non-reciprocal beamforming network with less complexity of the phase shifter and resolution requirements. The non-reciprocity is achieved through unidirectional amplifiers, different phase shifters with opposite progressive phases as well as a good Wilkinson power divider for isolation between the TX and RX paths. Two different progressive phases are also designed and shown here for the proof of concept. With one SP4T switch, and two passive low and high pass filters, eight different beam patterns were achieved four of them are for the transmit and the other four are for the receive paths. Any combination of the TX and RX paths can be used for different applications with a full-duplex scheme.
niversity); Mona Zaghloul (GWU)
1:50 PM – 133: A Wideband Non-Reciprocal Phased Array Antenna with Side Lobe Level Suppression
Hamed Tadayon (INRS University); Mansoor Dashti Ardakani (INRS University)*; Reza Karimian (The George Washington University); Shahrokh Ahmadi (The George Washington University); Mona Zaghloul (GWU)
A non-reciprocal antenna that can independently transmit and receive the signals in different directions is introduced in this paper. By using uni-directional amplifiers and different phase shifters a non-reciprocal antenna is achieved. Because the aperture of the antenna is the same for transmitting and receiving paths, the isolation between the two is important for practical applications. A non-uniform excitation by using a wideband feed-network microstrip structure improved the isolation between the two paths by more than 15 dB with an SLL suppression of better than 30 dB. Two different progressive phases by using low and high pass filters are shown for proof of concept. The concept can be applied for much smaller pattern resolution for space and commercial applications.
2:10 PM – 13: Beamforming with Uniform-Circular-Array and Ultrawideband-Throb Signal
Malek G. M. Hussain (Kuwait University)*
In this paper, the principle of beamforming using uniform circular array (UCA) antenna and ultrawideband (UWB)-throb signal is presented. The space-time resolution function of a UWB-throb signal received by a UCA antenna is derived and used to obtain the average-power beam pattern of the UCA. The elevation power pattern (EPP) and the azimuth power pattern (APP) for a UWB-throb signal and linear-frequency-modulated (LFM) signal, also referred to as chirp signal, received by a UCA are generated and compared. The EPP as well as the APP of the UWB-throb signal yield better angular resolution capability and have lower sidelobe levels than of he EPP and the APP of the LFM-chirp signal. It is shown that beam steering in the elevation plane of the UCA widens the beamwidth and influences the sidelobe structure of the power pattern, but not its general shape, while beam steering in the azimuth plane of the UCA is more robust and causes no deformation or widening of the power beampattern.
2:30 PM – 29: An Additively-Manufactured, Internally Metalized FUSE™ (IM-FUSE) Array
Eric Robinson (The MITRE Corporation)*; Franciso Ramos-Carrizosa (MITRE); Wajih Elsallal (MITRE); Carey Rappaport (Northeastern University)
In this paper, a new design technique is introduced which improves performance and lowers the fabrication cost of the Frequency-Scaled Ultra-Wideband Spectrum Element (FUSE™) aperture. The additively manufactured (AM) geometry is designed as a single block of polymer with hollow interior cavities corresponding to the radiating element shapes. An electroplating process is used to metalize only the interior surfaces of the cavities, enabling electrically isolated radiators with strong inter-element capacitive coupling. This technique results in a robust mechanical structure, eliminates the need for coaxial interposers, and utilizes low-cost plug-in connectors. The resulting simulated dual-polarized array achieves an active VSWR of 3.2:1 or less over a 7.3:1 frequency bandwidth while scanning to 60⁰ in in the E, H, and D scan planes with high Cross-Polarization Gain Isolation over most of the band.
2:50 PM – 154: Converged RF Phased Arrays Enabled by Silicon Photonics
Michael T Hoff (Lockheed Martin Corporation)*; Amit Kedia (Ayar Labs); Nhat Nguyen (Ayar Labs); Bob Paddison (Ayar Labs); Rick Stevens (Lockheed Martin Corporation)
This paper proposes a converged-aperture architecture to enable dynamic reconfiguration of spectral access between platform mission functions. Based on phased-array apertures, intra-platform data throughputs required to support the envisioned architecture are discussed, and integrated photonic transceivers are put forward as a critical enabling technology.
3:10 PM – 177: A PUMA Array Design for Space Applications
Thomas Hand (Lockheed Martin Space); Roger D Hasse (Lockheed Martin)*
This paper presents the design and experimental verification of a planar ultrawideband modular antenna (PUMA) antenna array intended for space applications. The low-profile, PCB design consists of linear, dual-polarized dipole elements that are arranged in a square lattice with offset phase centers. The PUMA array is optimized to achieve off-normal beam steering angles up to = 60 over a multi-octave bandwidth, and satisfies size, weight, and power (SWaP) requirements for future deployment on a space-based antenna array payload. The prototype PUMA array is designed to cover C-, X-, and Ku-bands. A prototype 15 15 dual-linear element array (225 elements, 25 connectorized) was designed, fabricated, and measured in a spherical near field range, where excellent agreement between modeled and measured radiation patterns are reported
3:30 PM – BREAK
4:00 PM – 30: Single-Polarization Vivaldi Antenna Array with Orthogonal Walls for Improved Polarization Purity
Rick Kindt (NRL)*; Jack Logan (NRL)
“Linearly polarized arrays of Vivaldi antennas are a common choice for ultra-wideband aperture implementations, often with a focus solely on bandwidth needs and less attention to polarization purity. With some forethought, it is possible to design Vivaldi antennas for low cross-polarization levels. In this paper, we highlight a simple approach to mitigate crosspolarization in two-dimensional array apertures of linearlypolarized Vivaldi antennas. This is demonstrated through a direct manufacturing approach that creates orthogonal metallic cross walls in arrays of all-metal linear Vivaldi flares. This demonstration has notable utility, as unlike dual-linear Vivaldi arrays, calibration of amplitude/phase via orthogonal channels cannot be used to correct polarization at a given frequency/angle in single-polarization Vivaldi arrays, as there are no orthogonal elements.”
4:20 PM – 31: Cross-Polarization Treatment in Linearly Polarized Vivaldi Array Apertures
Rick Kindt (NRL)*; Jack Logan (NRL)
“This paper examines how cross-polarization can be effectively reduced in two-dimensional array apertures of linearly-polarized Vivaldi antennas. In previous work it was demonstrated how metallic cross walls, positioned orthogonal to the linear Vivaldi antenna elements in a two-dimensional array, reduce cross-polarization significantly – e.g., -15dB levels for 45° diagonal plane scans. This cross-polarization mitigation technique is expanded upon by showing that slices in the metallic cross walls can further reduce cross-polarization, e.g. -25dB levels for 45° diagonal plane scans. For demonstration, an 8×8 single-pol. Vivaldi array comprising 8 rows of 8-element subarrays arranged onto a uniform grid with slots between elements is presented. Cross-polarization measurements are compared to infinite array simulations with and without ‘sliced’ metallic cards inserted (orthogonally) into the slots between radiating elements.”
4:40 PM – 119: A K- and V-Band Planar Dual-Polarized Tightly Coupled Dipole Array
Muhammad Hamza (Florida International University)*; Constantinos L. Zekios (Florida International University); Stavros Georgakopoulos (Florida International University)
A planar dual-polarized ultra-wideband array that covers both K and V bands is presented. The architecture relies on tightly coupled dipoles arranged in an egg-crate configuration and a novel capacitive via arrangement that pushes both, the common mode resonance and, the detrimental loop mode resonance, out of the band. To improve the impedance bandwidth and scanning ability, a Marchand balun feed network and a dielectric-based superstrate are respectively used. Infinite array simulations of our array demonstrate a bandwidth of 2.85:1 (22.25GHz to 64GHz) with VSWR<3 for a maximum scan-angle of ±45 for both E- and H-planes.
5:00 PM – 34: A Study of Uniformly Excited Linear Phased Array for Wideband Operation
Yu Ping Liu (Oakland University)*; Amanpreet Kaur (Oakland University)
In this paper a simple and intuitive equation is developed for a uniformly excited linear phased array for wideband frequency operation. This equation unifies phase delay, time delay, antenna element spacing, and operating frequency. Most importantly, the equation shows the array pattern can be normalized and multiplied into its final implementation of any frequency. This means existing array factors in use can be applied to a new design at any frequency. The equation is demonstrated with 3 possible real-world applications. The array pattern is first calculated using the expanded wideband equation and then verified using HFSS using a wideband linear tapered slot antenna for each design. In 2 of the examples, calculation and verification are done at 2 different bands to demonstrate the analysis is indeed normalized and can be multiplied into different frequency bands. The last example shows how the equation calculates element spacing to compensate for a squint-free phased array operating in wideband, which is easily achievable with Active Electronically Scanned Arrays (AESA). The equation provides an intuitive understanding of phased array characteristics in wideband, and it simplifies the design process, hopefully paving the way for further development of phased array systems.
Eden Vale C
Chairs: Kevin Rudd, DARPA; Ben Epstein, DARPA
1:30 PM – 49: Blind Adaptive Beamforming of Narrowband Signals using an Uncalibrated Antenna-Array by Machine Learning
Soeren Schoenbrod (Julia Computing Inc)*; Elliot Saba (Julia Computing Inc); Miguel Bazdresch (Rochester Institute of Technology); Steve Kelly (Julia Computing Inc); Tim Besard ( Julia Computing Inc); Keno M Fischer (Julia Computing Inc)
Multiple wireless communication systems compete within the same frequency range. The spatial domain adds an extra degree of freedom to the time and frequency domain. In this paper we introduce a machine learning model in the spatial domain designed to enhance the signal of interest and mitigate interfering signals. The method described does not require a calibrated antenna-array-RF-chain. It is based on a neural network that learns the structure of the signal of interest and separates it from other signals in the time, frequency and spatial domains. It does so without the need of any additional information and can very easily be used as a ballast to increase the Signal to Interference and Noise Ratio (SINR).
1:50 PM – 62: Abstraction and Acceleration of Tensor Processing for Element-Level Digital Arrays
Alexander Saad-Falcon (Georgia Tech Research Institute)*; Jonathan Beaudeau (Pareto Frontier); Jonathan Andreasen (Georgia Tech Research Institute); Michael McKinney (Georgia Tech); Ryan Westafer (Georgia Tech Research Institute); James C Kerce (Georgia Institute of Technology); Chris Barnes (Georgia Tech)
This paper describes an abstraction of tensor operations applicable to digital array radars (DARs) which enables adaptive on-array processing to meet changing requirements. An application programming interface (API) is presented that allows multiple algorithms to be realized with the same high-level description, with tunable parameters including array geometry, desired region of reconstruction (RoR), etc. This abstraction facilitates algorithm scaling and reconfiguration while also providing an efficient implementation on available hardware. Results of the abstraction are presented for two different algorithms solving a two-dimensional near-field imaging problem consisting of a single emitter in a scene. Both algorithms are tested on both simulated and measured data for comparison. Additionally, we explored automation tools for field-programmable gate array (FPGA) code development. We have shown that an abstracted FPGA implementation is capable of achieving 3-4 orders of magnitude speedup over traditional computing resources.
2:10 PM – 126: Rapid Prototyping Framework for Intelligent Arrays with Heterogeneous Computing
Garrett M Vanhoy (Peraton Labs)*; Marc Lichtman (Peraton Labs); Ray Hoare (Concurrent EDA); Claire Brevik (Concurrent EDA)
The availability of highly capable RF platforms with integrated heterogeneous compute has necessitated the need for software development frameworks that allow application designers to take advantage of these newly available capabilities. By leveraging open-source libraries and frameworks including GNU Radio, PyTorch, and Vitis AI, we have developed a framework that enables rapid prototyping and development of intelligent array processing applications and other SDR applications. This framework enables researchers and developers to deploy applications that make use of CPU, GPU, and Xilinx DPU resources, without the need to be a GPU or FPGA expert. Our initial kernel performance metrics show that this new ability will allow system designers to efficiently leverage trade-offs in system performance by effectively allocating resources across several processors.
2:30 PM – 101: Encoder-Decoder Networks for Self-Supervised Pretraining and Downstream Signal Bandwidth Regression on Digital Antenna Arrays
Rajib Bhattacharjea (DeepSig, Inc.)*; Nathan West (Deepsig, Inc.)
This work presents the first applications of self-supervised learning applied to data from digital antenna arrays. Encoder-decoder networks are pretrained on digital array data to perform a self-supervised noisy-reconstruction task called channel in-painting, in which the network infers the contents of array data that has been masked with zeros. The self-supervised step requires no human-labeled data. The encoder architecture and weights from pretraining are then transferred to a new network with a task-specific decoder, and the new network is trained on a small volume of labeled data. We show that pretraining on the unlabeled data allows the new network to perform the task of bandwidth regression on the digital array data better than an equivalent network that is trained on the same labeled data from random initialization.
2:50 PM – 112: Zoom Out: Abstractions for Efficient Radar Algorithms on COTS architecture
Tze Meng Low (Carnegie Mellon University)*; Yueji Chi (Carnegie Mellon University); James Hoe (Carnegie Mellon University); Swarun Kumar (Carnegie Mellon University); Akarsh Prabhakara (Carnegie Mellon University); Laixi Shi (Carnegie Mellon University); upasana sridhar (Carnegie Mellon University); Nicholai Tukanov (Carnegie Mellon University); Chengyue Wang (Carnegie Mellon University); Yuchen Wu (Carnegie Mellon University)
“The advent of machine learning has resulted in the rapid development of machine learning accelerators that are capable of computing tensor operations efficiently. Specifically, these accelerators compute matrix-matrix multiplication, a key routine in linear algebra libraries and machine learning. While using the accelerators would result in high performance radar signal processing, the algorithms used often require significant redesign in order to efficiently map them on to existing machine-learning hardware. In this paper, we show that higher levels of abstraction facilitate the efficient mapping of array algorithms onto commercial-off-the-shelf (COTS) machine learning hardware that results in higher performance both in terms of execution time and/or throughput. Furthermore, similar levels of abstraction can be used to design efficient implementations of ML algorithms for radar processing, resulting in improved radar capabilities.”
3:10 PM – 145: Deep Learning with Interference Training for Adaptive Radar Beamforming
David Hartman (Bluehalo)*; Nof Abuzainab (BlueHalo); Tugba Erpek (IAI); Yalin Sagduyu (IAI); Kemal Davaslioglu (IAI)
“Phased arrays electronically shape and steer electromagnetic beams for transmission or reception of signals. The basic operation of beamforming can be expressed as a tensor operation, thereby laying the foundation of using deep neural networks for adaptive beamforming in radar systems. In this paper, we formulate adaptive receiver beamforming under interference effects as tensor operations and train a deep neural
network (as a regression model) along with interference training to boost beamforming capabilities and mitigate interference effects in radar systems. The resulting formulation operates with small memory footprint and low latency in inference time, while effectively suppressing both noise and interference (such as barrage jamming) effects.”
3:30 PM – BREAK
4:00 PM – 87: Fast Adaptive Beamforming Using Deep Learning for Digital Phased Array Radars
Yoon-SL Kim (Univ. of Okla., ARRC)*; David Schvartzman (Univ. of Okla., ARRC); Bob Palmer (Univ. of Okla., ARRC); Tian-you Yu (Univ. of Okla., ARRC)
The all-digital polarimetric phased array radar has the potential to achieve high temporal and spatial resolution requirements needed for polarimetric meteorological observations. It offers maximum flexibility in scanning strategies that support the use of the traditional “pencil” beams, spoiled beams, and/or multiple beams. Two digital beamforming (DBF) methods are of interest for polarimetric meteorological measurements, the Fourier and Capon methods. While beamforming weights can be pre-computed with the conventional Fourier DBF method, they are computed adaptively with the Capon method. The Capon method can provide improved data quality over the Fourier method by lowering antenna sidelobe levels in directions with high return power, and improving angular resolution of the scanning beam. However, it is challenging to implement the Capon method in real time due to high computational cost. This paper presents a computationally efficient Deep Learning Adaptive digital beamForming (DLAF) method using a neural network trained with the Capon method. The proposed DLAF model is evaluated using a simulated point target and simulated weather signals for a planar digital array architecture. The performance of DLAF is measured by its computational efficiency compared to the Capon method and its ability to mitigate contamination coming from antenna sidelobes. Preliminary results show that DLAF can be used to significantly reduce DBF computation time while improving data quality of observations.
4:20 PM – 117: Fast ML-Assisted Interference Estimation and Suppression for Digital Phased Array Radar
Danijela Cabric (University of California, Los Angeles)*; Ruifu Li (University of California, Los Angeles); Shamik Sarkar (University of California, Los Angeles); Jacquelyn Vitaz (Raytheon Technologies); Patrick Powers (Raytheon Technologies); James McGraw (Raytheon Technologies)
Radars must operate in environments where interference can potentially degrade performance. With a fully digital array, classical adaptive radar signal processing methods suffer from higher order of computations and latency overhead. This is a challenging problem in the era of dynamic spectrum sharing where the interference sources can be highly variable. In this paper, we propose a fast ML-assisted method for detection of interference sources and estimation of their directions of arrival. These estimates are used for computation of adaptive weights with a covariance-based method that reduces the number of complex matrix inversion operations. Using simulation-based evaluations, we compare the results of our proposed approach with the classical methods.
Emerson
Chairs: George Che, Georgia Tech Research Institute; Adilson Cardoso, Raytheon
1:30 PM – 14: An RF reference signal distribution system for suppressing phase fluctuations during transmission
Kae Morita (Mitsubishi Electric Corporation)*; Jun Shimokawatoko (Mitsubishi Electric Corporation); Osamu Wada (Mitsubishi Electric Corporation); Hiroyuki Mizutani (Mitsubishi Electric Corporation); Hideyuki Nakamizo (Mitsubishi Electric Corporation)
In this paper, we propose a radio frequency (RF) reference signal distribution system with an analog phase shifter for suppressing the phase fluctuations occurring during transmission, caused by transmission line vibrations. The system was found to detect the phase fluctuations occurring in the transmission line and was able to cancel them by applying antiphase fluctuations to the RF reference signal using an analog phase shifter. We derived a calculation method for determining the suppression level with respect to the phase fluctuation frequencies, and this method was validated by the measurement results. The results also demonstrated the performance of the proposed system because it was able to achieve a phase fluctuation suppression level of 1/50 at a phase fluctuation frequency of 1 kHz. Thus, the proposed system holds major implications for ensuring the stable operation of distributed phased array antenna systems.
1:50 PM – 38: A High-Resolution Vector Modulator Design for Ultra-Wideband Active Phased Array Systems
Ahmet Hasturk (ASELSAN INC.)*; Nursel Akçam (Gazi University)
Ultra-wideband phased array systems are mostly desired with regard to narrow band systems due to the usage of multifunctionality such as detection, tracking and imaging applications. In this work, an innovative vector modulator design with using 1:2 balun based bi-phase modulator is presented. Designed vector modulator can be used for phase shifting and amplitude controlling of active phased array systems. Moreover, vector modulator is designed reciprocally for the usage of transmit and/or receive applications.
2:10 PM – 70: High Performance S-Band Dual Transmit/Receive Module for Active Phased Array Radar
Virendra Kumar (Defence Research and Development Organisation(DRDO))*; Shreeshail . (Defence Research and Development Organisation(DRDO)); Upendra Shankar Pandey (Defence Research and Development Organisation(DRDO)); K SREENIVASULU (DRDO); Beenamole K.S. (Defence Research and Development Organisation(DRDO)); Ravi Gangwar (IIT(ISM) Dhanbad)
This paper presents the electrical performance and construction details of the S-band dual transmit/ receive module (DTRM) over 400 MHz bandwidth for an active phased array radar. Each T/R channel of DTRM delivers > 120W peak power with ≥ 38% module efficiency. The T/R module operates up to one milli-sec pulse width and ≤ 20% duty cycle. The T/R module has ≈ 30±2 dB receive gain and exhibits < 3.5 dB noise figure over 400 MHz bandwidth and -100C to +550C temperature range. It is designed for a high dynamic range with good sensitivity and exhibits > +4dBm P1dB point and has > +22 dBm OIP3. Each T/R channel is designed in common leg architecture with a 6- bit digital phase shifter, 6-bit digital attenuator, and a single-pole double-throw (SPDT) switch to reduce the monolithic microwave integrated circuits (MMICs) count and cost of the T/R module. The DTRM is realized in an Aluminium 6061-T6 casing and mounted on a heat exchanger for efficient thermal management. The DTRM has a 26-pin D-type high-density (HD) connector and blind-mate adapter (BMA) for the RF interface. It is realized with the physical dimension of ≈ 175.0 mm(L) x 80.0 mm(W) x 26.0 mm (H) (mm) and has < 0.6 Kg weight for modern active phased arrays.
2:30 PM – 88: Multi-Harmonic Beam Steering of TMLAA Employing TLBO
SUNEEL D VARMA (NIT WARANGAL)*; GOPI RAM (NIT WARANGAL); ARUN KUMAR (NIT WARANGAL)
“This paper aims to address the utilization of harmonic beams radiated from the Time-Modulated Linear Antenna Array (TMLAA) by focusing the beams in the Angle of Arrival (AoA) direction. The focusing of the frst and second harmonic beams with adequate power is achieved by employing
the optimized switching schemes. The switching sequence ON duration optimization is conducted by Teaching Learning Based Optimization (TLBO). The optimization is conducted for three cases, to steer the frst positive harmonic beam to 300, 450, and 600. The performance of the TLBO is compared with the evolutionary algorithms Differential Evolution (DE) and Particle Swarm Optimization (PSO). TLBO optimization results in sidelobe level (SLL) in fundamental and harmonic beams below −15 dB. The simulation results convey that the TLBO performs superior to DE and PSO in focusing the harmonic beams in the AoA direction with suppressed SLL and enhanced power”
2:50 PM – 93: A Power Detector for Built-In Self Test of 4-Channel Beamforming Transceiver in Phased Array Systems
Soo-Chang Chae (Korea Electronics Technology Institute)*; Chung-Geun Jang (Korea Electronics Technology Institute); Soo-Jung Kim (Korea Electronics Technology Institute); Kwang-Ho Ahn (Korea Electronics Technology Institute); Ki-Jin Kim (Korea Electronics Technology Institute)
A power detector is proposed to provide the BIST function of a millimeter-wave 4-channel transceiver IC. The proposed transceiver IC and power detector are designed to operate at 28 GHz in 65-nm CMOS technology. The transceiver includes 4 RF channels, and 2 power detectors are also included to provide the built-in self-test(BIST) function of the transceiver. The power detector is placed between two RF channels, receives a signal coupled from the RF channel as an input, and outputs a DC output voltage. The coupled signal is combined and input to a power detector, providing a comparison of the deviation between the RF channels by controlling the magnitude and phase. The power detector is designed to have a wide dynamic range. The DC output voltage response of the power detector satisfies the linearity error within ± 1 dB in the range of 26 dB, and the linear slope is −20 mV/dB.
3:10 PM – 122: Constraints of Designing PCB Technology Based Tile-Type TR Core Modules for Scalable X Band AESA Architectures
Kaan Temir (Aselsan Inc.)*; Ayse Rana BAL (Aselsan Inc)
This study discusses some critical parameters and design constraints required to realize an X band TR module especially used for tile-architecture active phased array Radar/EW systems. The designed structure, based on multilayer PCB technology which reduce the production cost, is a scalable core unit for X band AESA applications. It consists of multi-channel T/R microwave circuits, beamforming networks, power, protection and control units, functional testing blocks, and solderless connection interfaces both for antenna and system manifolds. It achieves outstanding performance satisfying the SWaP-C requirements for air platforms. Each channel has more than 4W figure of merit (Pt/NF) [1] together with at least 18dB receive gain. The realized multi-channel TR module has a compact mechanical packaging to satisfy thermal management, lower than 2cm in height and 100 gr in weight
3:30 PM – BREAK
4:00 PM – 131: Low-Cost UHF Phased Array System Architecture for Small Satellite Ground Stations
Christopher Conrad (University of Malta)*; Andre Micallef (University of Malta); Marc A Azzopardi (University of Malta); Victor Buttigieg (University of Malta); Charles Grech (University of Malta)
The space industry has shifted its focus to the development of low-cost satellites and large satellite constellations. Notably, most nano-satellites in low Earth orbit operate at UHF (P-band) frequencies to leverage the use of low-cost commercial off-the-shelf electronics. Such constellations would benefit from the rapid steering of multiple beams offered by a phased array antenna (PAA) ground station (GS). The cost of such systems, however, is not conducive to the low-cost philosophy of the satellites. While several universities have identified the need for a low-cost UHF PAA GS, no feasible design or prototype has yet been developed that is suitable for low-cost applications involving PAAs with a large number of elements. This paper proposes and demonstrates a subarray-digital architecture with a novel two-stage analog beamforming segment to optimize resource usage within the PAA, by allowing for the dynamic reconfiguration of the number of required digital ports. It further leverages several cost reduction techniques to design a modular and scalable transmit/receive module and ancillary geodesic dome PAA. An operational prototype is constructed and used to validate and characterize the implemented design. This successfully reduces the costs of a PAA GS while retaining the associated performance benefits.
4:20 PM – 150: A 5-33 GHz 8-Channel Transmit Beamformer with Peak Power of 14 dBm for X/Ku/Ka-band SATCOM Applications
Oguz Kazan (University of California, San Diego)*; Zhaoxin Hu (University of California, San Diego); Abdulrahman Alhamed (University of California, San Diego); Gabriel M. Rebeiz (Nil)
This paper presents a 5-33 GHz 8-channel transmit beamformer implemented in 90nm SiGe BiCMOS HBT technology. Each channel is composed of a wideband two-stage power-amplifier (PA), a phase-shifter (PS), a variable gain amplifier (VGA) and single-ended to differential converter (S2D). The input RF power is distributed to the 8-channels using a two-stage Wilkinson network and active dividers. The measured small-signal gain is 24-27 dB at 5-33 GHz with 5-bit phase-shifter operation and > 20 dB gain control. A peak OP1dB and OPsat of 13-14 dBm is achieved at Ku-band. To author’s knowledge, this work achieves the widest bandwidth Tx beamforming chip. Application areas are ground terminals capable of communications with X, Ku and Ka-band satellite constellations.
4:40 PM – 166: Octal Transmit Receive Module for Wideband Phased Arrays
K SREENIVASULU (DRDO)*; D Srinivas Rao (LRDE DRDO); Swaraj Varshney (LRDE DRDO); Hemanth Gaddam (RFMW Innovations lab); KP Ray (Department of Electronics Engineering, Defence Institute of Advanced Technology, Girinagar, Pune)
“Active Phased array systems are widely used in
Radar, Electronic Warfare (EW) and Communication applications. The SWaP-CR of any active phased array system is dictated fully by key Transmit/Receive Modules. This paper presents on the design aspects of Octal Transmit and Receive Module (OTRM) for a 4×8 element wideband phased array operating over more than 2.5 octaves Bandwidth for EW application. A compact and efficient GaN based OTRM is designed and realized to deliver CW output power of 38dBm (min) per TR channel. A novel scheme of switched phase shifters is employed in OTRM to cover 5GHz operating bandwidth.”
Lincoln Cambridge
Chairs: Philip Zurek MIT Lincoln Laboratory; Mark McClure, Systems & Technology Research
1:30 PM – 32: A Closed-form Expression for the Directivity of Planar Arrays with Arbitrary Topologies and Element Patterns
Colin Mussman (Penn State)*; Douglas Werner (Penn State University)
This work presents a new analytical (i.e., closed-form) solution to the directivity of a planar array with arbitrary topology. The derived method also makes use of a novel element pattern model which can take into account radial asymmetries in both θ and ϕ: a generic pattern suitable for a wide range of applications. The analytical method is validated by numerical integration using Simpson’s 1/3rd method. The analytical method enables fast topology optimization of phased array designs by avoiding time-consuming numerical integration.
1:50 PM – 60: Simultaneous Multi-Band, Multi-Beam, and Multi-Function TX/RX Phased Array Systems
Dennis Prather (University of Delaware)*; Christopher Schuetz (Phase Sensitive Innovations)
This paper presents new TX and RX phased array systems that provide simultaneous multi-band, multi-beam, and multi-function operation over the millimeter wave region of the electromagnetic spectrum. The overall system uses separate TX and RX arrays that are based on optical up- and down-conversion, as the means to implement beam forming with near unlimited beam-bandwidth-products. It does so in a non-blocking and multi-tasking manner, which enables numerous commercial and DoD applications.
2:10 PM – 85: Highly Directive Compact Multiband MIMO Array Antennas with Improved Gain for 5G Wireless Communication System
Owais Khan (University of IT and Emerging Sciences); Muhammad Anab (UET); Kiran Fayyaz (University of IT and Emerging Sciences); shahid khan (comsast University Islamabad, Abbottabad Campus); Farhad Arpanaei (Universidad Carlos III de Madrid); Mariana Dalarsson (KTH Royal Institute of Technology); Mohammad Alibakhshikenari (Universidad Carlos III de Madrid)*
A novel wide dual-band, Multiple-Input Multiple-Output (MIMO) antenna design for the upcoming fifth generation (5G) wireless communication is presented in this work. The size of single element of the proposed MIMO configuration is 4×5 mm2 having L-shaped slot at the top edge. Rogers TMM4 with thickness of 0.508 mm having relative permittivity of 4.5 is used as a substrate material. Resonating frequencies of single antenna element are 40.15, 67.80 and 91.23 GHz with a wide impedance bandwidth of 2.22 and 34.43 GHz, respectively. The return loss at resonating frequencies are -29.25, -66.30. and -20.00 dB with a good gain of 5.51, 4.27 and 3.70 dBi, respectively. The overall size of proposed 1×2 MIMO antenna is 4×7 mm2 with a separation of 3.6 mm in between two elements and 0.6 mm separation between the edges and elements. The resonating frequencies of the proposed MIMO antenna are 40.36 GHz with reasonable gain of 4.62 dBi, and 67.59 and 95.73 GHz with improved gain of 5.42 and 5.70 dBi, respectively. The simulated return loss below -10db at resonating frequencies are -21.92, -63.38 and -27.87 dB, respectively. Inter-port isolation of above 20 dB throughout the operating frequencies, is achieved without using any complex technique. Envelope Correlation Coefficient (ECC) and Diversity Gain (DG), are important MIMO antenna parameters are less than 0.001 and 10 dB respectively. The proposed design with a high radiation efficiency at resonating frequencies is a good candidate for the satellite and radar communication as the achieved operating range lies in the proposed Ka-band (26-40 GHz), V-band (40-75 GHz), E-band (60-90 GHz) and W-band (75-110 GHz).
2:30 PM – 105: RF CMOS Front-end with Antenna for 2.4 GHz Transceiver and Internet of Thing Applications
Wen-Cheng Lai (National Taiwan University of Science and Technology)*
The promoted letter presents wireless RFIC frontend for ultra-wideband applications. The promoted wireless transceiver integration includes of power amplifier (PA) with pre-distorter, bandpass filter, two mixers, low noise amplifier (LNA) with balun in parallel and adjustable gain control (AGC). The RF throw radio (TR) switch circuit is converting from antenna and used the same voltage-controlled oscillator as local oscillator design. The PA design promotes linearity conversion gain more than 25 dB, the output 1-dB compression point (OP 1dB) more than 10 dBm and power added efficiency (PAE) enhance to 12%, respectively. The promoted LNA promotes return loss of input enhance to 21.1dB, return loss of output enhance to 33.5dB dB, the exhibits gain of 13.3 dB, the exhibits noise figure of 6 dB, the exhibits input 3rd order intercept point (IIP3) of -4.16 dBm, the exhibits input 1-dB compression point (IP 1dB) of -11.5 dBm, respectively. The proposed adjustable gain control (AGC) presents gain tuning range from 13.3dB ~ 1.4dB, the noise figure tuning range from 6dB ~ 10.83dB, respectively. The implemented 2.4GHz transceiver using CMOS technology has experimental rely on conditions, distances and concurrently complies with wireless performance requirement.
2:50 PM – 134: A 24 GHz Flexible 10×10 Phased Array Antenna for 3D Beam Steering Based V2V Applications
Karthik Kakaraparty (university of north texas)*; Ifana Mahbub (University of North Texas)
This paper presents a flexible 10×10 phased-array antenna for efficient and high-gain 3D beam steering applications. The proposed antenna array consists of 25 quadrants of 2×2 unit cells, wherein each 2×2 unit cell is coaxially fed. The 45° phase-shifting lines are incorporated in the feeding paths to facilitate the wide beam steering range. The dimensions of the proposed phased array antenna are 90x90x0.324 mm3. Simulation results show that the proposed phased-array antenna has a resonating frequency at 24 GHz with an operational bandwidth from 23.64 GHz to 24.31 GHz and a high gain of 29.4 dBi. The array exhibits a maximum beam steering range of 149.8° in the Θ axis and 120° in the Φ axis with a gain variation less than 0.9 dBi. The proposed flexible phased antenna array is suitable for placement on curved surfaces.
3:10 PM – 174: 5G Ku-band Radar Array for Wide-Area Surveillance
Bill Weedon (Applied Radar)*
Phased array chipsets (so-called “5G array chips”) recently developed primarily for high-volume terrestrial and satellite communications applications may potentially be repurposed for wide-area radar surveillance applications. In this paper, we explore the use of a commercially-available Ku-band chipset to build such an array, with the goal of developing a low-cost array with small form-factor, covering a wide search volume. Such an array is inherently power-limited, and the use of a high transmit duty cycle with a narrow pencil beam that can be accurately steered on both transmit and receive are used to compensate for some of the shortcomings in total transmit power and noise figure. The goal is to develop general-purpose transmit/receive array panels that may be used for a variety of industrial applications, including ground-based, vehicular and airborne systems. Initial design work has been performed under internal R&D funding, and the first array panel prototypes are being prepared for fabrication. The final paper will include initial test results of the array prototypes, and discussion of potential applications.
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