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1. Cloaking and Decoupling of Interleaved Microstrip Monopole Arrays at 28 GHz and 39 GHz Using Elliptical Metasurfaces for 5G Wireless Applications

   S. Pawar, S. Mastromatteo (July 2020, 2020 IEEE AP-S/URSI Conference)

   null (Ed.)

   Two tightly spaced, interleaved microstrip monopole antenna arrays operating at microwave frequencies are decoupled by employing mantle cloaking method. We use elliptical metasurfaces specifically tailored for the cross-coupled elements of the distinct arrays and show that by wrapping each antenna element with the metasurface cloak, the undesired cross-coupling between the elements at frequencies 28 GHz and 39 GHz is eliminated, restoring their radiation patterns as if the arrays were isolated from each other. In this paper, the cloaking and decoupling effect is scrutinized and evaluated to improve the functionality of the coupled arrays in terms of their radiation patterns and realized gain, when all the antenna elements are excited simultaneously. Consequently, the monopole antenna arrays, even though placed in close proximity, can radiate independently for a wide range of beam scanning angles. 

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2. Design of 145 GHz BPSK SDR on RF-SoC

   Karunanayke, K; Weerasooriya, H; Rathnasekera, G; Singh, A; Jornet, J; Rappaport, T; Madanayake, A (May 2024, IEEE Xplore)

   Wireless links at sub-THz bands require low-SWaP SDR modems. We report early design experimentation of an SDR operating in the 130–150 GHz band, with ASK/BPSK/QPSK modulation on I/Q channels, at a maximum data rate of 128 Mbps. The design utilizes 110–170 GHz front-ends from Virginia Diodes, and Xilinx RF-SoC ZCU-111 for DSP operations. A 1 GHz baseband example at 145.5 GHz is provided. The experiment uses horn antennas with 21 dB gain. The SNR is about 40 dB without cross correlation gain in the detector which provides an additional 15 dB in link margin. Real-time bit rate of 128 Mbps is achieved. Example applications include vehicle-to-vehicle, vehicle-to-infrastructure, backhaul, device-to-aerostat. This paper provides a platform from which further design work will lead to increased data rate and/or range, and enhance security through encryption. Future designs will facilitate digital interfaces, such as, ethernet, AXI, PCIe and USB-C. 

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3. A Wideband Stacked Patch-Patch Antenna with Hybrid Perturbations for Circular Polarization

   https://doi.org/10.1109/APS/URSI47566.2021.9703820.  

   M. M. Hossain, S. S. (February 2022, 2021 IEEE International Symposium on Antennas and Propagation and USNC-URSI Radio Science Meeting (APS/URSI))

   This paper presents a wideband circularly polarized antenna for small satellites to be used with NASA Near- Earth Networks (NEN). This single-fed stacked antenna utilizes the electromagnetic coupling concept and is usable with a duplex transceiver. The circularly-polarized antenna employs hybrid perturbations on stacked patches and covers NASA NEN’s both uplink and downlink frequencies, thus replacing the conventional requirement of two separate antennas. It provides a notable wide axial ratio (AR) < 3 dB bandwidth of 1.16 GHz from 7.02 GHz to 8.18 GHz (15.3%). The optimized patch dimensions provide 34.6% VSWR ~ 2 bandwidth from 6,525 MHz to 9,253 MHz. The overall antenna size is 17 mm × 17 mm × 6.6 mm, and has a peak gain of 7.9 dBi. This proposed antenna will overcome solar cell space constraint on smallsat’s outer wall by saving at least 50% area required by the conventional two-antenna method. 

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4. Design, Simulation and Comparison of two 15mm × 15mm UWB Antennas with Modified Ground Patch for High Data-rate Wireless Electrophysiological Recording Application

   https://doi.org/10.1109/WMCS52222.2021.9493275  

   Patwary, Adnan Basir; Mahbub, Ifana (May 2021, 2021 IEEE Texas Symposium on Wireless and Microwave Circuits and Systems (WMCS))

   For the diagnosis and treatment of various chronic neurological diseases such as Epilepsy, Seizure and, chronic pain, a long-term electrophysiological recording and stimulation are required for the patients. This type of study can be done through implantable neuromodulation devices. One of the key challenges in designing such implantable medical devices is the size restriction. Even the antennas transmitting the recorded signals must be small, miniaturized, and light-weight in order for the small animals used in the clinical studies to carry it easily. In this paper, two 15mm×15mm antennas are designed which have ultra-wide bandwidths making them suitable for the high data rate electrophysiological recording applications. The proposed antennas are bidirectional and small in size making them suitable to be added to the headstage based electrophysiological recording devices. Both antennas have a similar radiating patches with each ground patch modified by creating two different slots. A comparison of the proposed antenna is presented in the paper where both antennas operate within 4.7 GHz to 8.3 GHz and having average gain above 4.35 dBi. Though the proposed antennas are 40% smaller in size, they have 6% higher gain compared to the state of the arts. 

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5. Design of a Cyberattack Resilient 77 GHz Automotive Radar Sensor

   https://doi.org/10.3390/electronics9040573  

   Toker, Onur; Alsweiss, Suleiman (April 2020, Electronics)

   In this paper, we propose a novel 77 GHz automotive radar sensor, and demonstrate its cyberattack resilience using real measurements. The proposed system is built upon a standard Frequency Modulated Continuous Wave (FMCW) radar RF-front end, and the novelty is in the DSP algorithm used at the firmware level. All attack scenarios are based on real radar signals generated by Texas Instruments AWR series 77 GHz radars, and all measurements are done using the same radar family. For sensor networks, including interconnected autonomous vehicles sharing radar measurements, cyberattacks at the network/communication layer is a known critical problem, and has been addressed by several different researchers. What is addressed in this paper is cyberattacks at the physical layer, that is, adversarial agents generating 77 GHz electromagnetic waves which may cause a false target detection, false distance/velocity estimation, or not detecting an existing target. The main algorithm proposed in this paper is not a predictive filtering based cyberattack detection scheme where an “unusual” difference between measured and predicted values triggers an alarm. The core idea is based on a kind of physical challenge-response authentication, and its integration into the radar DSP firmware. 

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