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1. A Wideband CPW-Fed Monopole Antenna for High-Temperature Applications

   https://doi.org/10.23919/USNC-URSI52669.2022.9887504  

   Mertvyy, Aleks; Renk, Noah; Bigelow, Vincent; Younes, Bachir Adham; Sekhar, Praveen; Karacolak, Tutku (September 2022, 2022 IEEE USNC-URSI Radio Science Meeting)

   As the advancement of wireless devices and their applications progress, it is important to produce novel aspects of a usual design to expand their capabilities. One such application could be for extreme circumstances that would include high temperatures. In order to approach this issue, a new substrate has been proposed to implement high-temperature devices. Zirconia Ribbon Ceramic (ZRC) is made of YSZ with high temperature tolerance, smooth surface, moisture resistant, mechanically robust, and low thermal mass properties [1] . Recent publications has demonstrated the suitability of ZRC for implementing functional devices [ 1 –​3 ]. Due to this material’s durability and capability of resisting high temperatures, it provides a desirable opportunity of applying this material as a substrate for patch antenna applications. The application of this material, however, requires the understanding of its electrical properties and behavior. This proposed material has a high relative permittivity and a low loss tangent as compared to traditionally available substrates. The high dielectric constant of ZRC along with low loss characteristics allows for realizing efficient wireless systems with smaller form factor. In this study, a wideband patch antenna on ZRC substrate is proposed for high-temperature environments. The antenna operates within 1.89 GHz–3 GHz frequency range, and can be used for WLAN, ISM band, and S-band applications. 

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2. Amphibious epidermal area networks for uninterrupted wireless data and power transfer

   https://doi.org/10.1038/s41467-023-43344-6  

   Hajiaghajani, Amirhossein; Rwei, Patrick; Afandizadeh Zargari, Amir Hosein; Escobar, Alberto Ranier; Kurdahi, Fadi; Khine, Michelle; Tseng, Peter (November 2023, Nature Communications)

   Abstract The human body exhibits complex, spatially distributed chemo-electro-mechanical processes that must be properly captured for emerging applications in virtual/augmented reality, precision health, activity monitoring, bionics, and more. A key factor in enabling such applications involves the seamless integration of multipurpose wearable sensors across the human body in different environments, spanning from indoor settings to outdoor landscapes. Here, we report a versatile epidermal body area network ecosystem that enables wireless power and data transmission to and from battery-free wearable sensors with continuous functionality from dry to underwater settings. This is achieved through an artificial near field propagation across the chain of biocompatible, magneto-inductive metamaterials in the form of stretchable waterborne skin patches—these are fully compatible with pre-existing consumer electronics. Our approach offers uninterrupted, self-powered communication for human status monitoring in harsh environments where traditional wireless solutions (such as Bluetooth, Wi-Fi or cellular) are unable to communicate reliably. 

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3. Reinforcement Learning Based Power-Optimal Usage of Beamforming Antenna Array for Multi-Way Wireless Communication in Vehicular Traffic Environments

   Suhasini Kommarraju and Abhijit Chatterjee (August 2022, Midwest Symposium on Circuits and Systems)

   There has been recent work on the design of antenna arrays for beamforming in dynamic evolving environments such as in vehicle-to-vehicle communication systems. A key problem is that of determining how to optimally use a large antenna array to communicate with multiple spatially located vehicles in dynamically changing channel conditions with minimal co-channel interference while minimizing overall power consumption of the wireless system. We envision disjoint subsets of antennas in the array being used to direct beams concurrently to different vehicles. The number of antennas, gain and phase of each RF-chain driving an antenna are optimized dynamically using a constrained quadratic cost formulation encompassing channel quality, interference and power consumption. This quadratic optimization problem is solved using behavior constrained bandit algorithm, a reinforcement learning based technique. A gaussian kernel is used to perform data clustering of vehicle environment and resulting solutions, allowing quick bootstrapping of the bandit solver to find optimal array configurations in real-time vehicle environments. Simulation studies prove the viability of the proposed scheme. 

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4. Detection of Crack Initiation and Growth Using Fiber Bragg Grating Sensors Embedded into Metal Structures through Ultrasonic Additive Manufacturing

   https://doi.org/10.3390/s19224917  

   Chilelli, Sean K.; Schomer, John J.; Dapino, Marcelo J. (November 2019, Sensors)

   Structural health monitoring (SHM) is a rapidly growing field focused on detecting damage in complex systems before catastrophic failure occurs. Advanced sensor technologies are necessary to fully harness SHM in applications involving harsh or remote environments, life-critical systems, mass-production vehicles, robotic systems, and others. Fiber Bragg Grating (FBG) sensors are attractive for in-situ health monitoring due to their resistance to electromagnetic noise, ability to be multiplexed, and accurate real-time operation. Ultrasonic additive manufacturing (UAM) has been demonstrated for solid-state fabrication of 3D structures with embedded FBG sensors. In this paper, UAM-embedded FBG sensors are investigated with a focus on SHM applications. FBG sensors embedded in an aluminum matrix 3 mm from the initiation site are shown to resolve a minimum crack length of 0.286 ± 0.033 mm and track crack growth until near failure. Accurate crack detection is also demonstrated from FBGs placed 6 mm and 9 mm from the crack initiation site. Regular acrylate-coated FBG sensors are shown to repeatably work at temperatures up to 300 ∘ C once embedded with the UAM process. 

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5. Post-Radiation Fault Analysis of a High Reliability FPGA Linux SoC

   https://doi.org/10.1145/3543622.3573191  

   Wilson, Andrew Elbert; Baker, Nathan; Campbell, Ethan; Sahleen, Jackson; Wirthlin, Michael (February 2023, Proceedings of the 2023 ACM/SIGDA International Symposium on Field Programmable Gate Arrays)

   FPGAs are increasingly being used in space and other harsh radiation environments. However, SRAM-based FPGAs are susceptible to radiation in these environments and experience upsets within the configuration memory (CRAM), causing design failure. The effects of CRAM upsets can be mitigated using triple-modular redundancy and configuration scrubbing. This work investigates the reliability of a soft RISC-V SoC system executing the Linux operating system mitigated by TMR and configuration scrubbing. In particular, this paper analyzes the failures of this triplicated system observed at a high-energy neutron radiation experiment. Using a bitstream fault analysis tool, the failures of this system caused by CRAM upsets are traced back to the affected FPGA resource and design logic. This fault analysis identifies the interconnect and I/O as the most vulnerable FPGA resources and the DDR controller logic as the design logic most likely to cause a failure. By identifying the FPGA resources and design logic causing failures in this TMR system, additional design enhancements are proposed to create a more reliable design for harsh radiation environments. 

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