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  1. Electromagnetic shielding often requires the integration of thick shielding structures in the form of metal casings, walls, or via arrays. These shields typically isolate the entire package from external or internal noise sources. In some cases, they also isolate components within the package. However, integration of shielding structures with the required performance creates miniaturization and fabrication constraints, and results in longer product development cycle times. To address these limitations, a novel approach is presented for component- and package-level shielding. This approach is based on electromagnetic interference (EMI) shield integration through a microassembly of prefabricated shields inside microslots in packages and printed circuit boards (PCBs). This approach eliminates many of the design and process constraints during the shield integration within packages. Various design options were considered to mitigate capacitive and inductive coupling between representative microstrip lines that act as aggressors and victims. Three types of EMI shielding architectures, U-shaped, inverted-L-shaped, and T-shaped, were investigated with 17.5 μm copper. The fabricated EMI shields were studied for their shield performance, both as a compartmental shield between specific components and as a conformal shield from external and internal noises. The role of the ground termination was also investigated to further optimize the shielding performance. 
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    Free, publicly-accessible full text available January 1, 2025
  2. Reconfigurable Intelligent Surfaces (RIS) also known as Intelligent Reflecting Surfaces (IRS) often depend upon metasurfaces. These typically comprise of a large array of passive elements that can be fabricated to modulate reflection amplitude or phase or both to create tunable functions that are independently controlled. Various RIS are developed to improve spectral efficiency through ultrawideband antennas, enhanced beamforming with higher gain and bandwidth, spatial reconfigurability, selective and adjustable isolation, and other desired features. Several approaches to tune the RIS performance are being explored. This paper reviews the primary approaches and the benefit of emerging tunable nanomaterials in achieving such RIS functions. Designs with 1-bit and 6-bit phase shifters are discussed in the first part. Various opportunities with nanomaterials and nanodevices to induce such phase shifts are discussed in the last part of the paper. 
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    Free, publicly-accessible full text available October 22, 2024
  3. Wireless power transmission is becoming a key technology in realizing future sensor nodes. Current approaches are based on inductive links or RF telemetry, both face limitations in achieving higher power densities. Multiferroic telemetry can address this challenge and provide a new approach for remote powering. This paper describes an integrated piezoelectric film on magnetostrictive carriers to achieve highly-efficient multiferroic functions. Various multi-layered architectures were investigated for output power performance. The multiferroic flexible stacks subsequently integrated with diode rectifier topologies and storage capacitors to generate the desired output. Results demonstrate new power telemetry opportunities with advanced material stacks with flex package integration. 
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  4. null (Ed.)
    Abstract: Communication systems of the future will require hundreds of independent spatial channels achieved through dense antenna arrays connected to digital signal processing software defined radios. The cost and complexity of data converters are a significant concern with systems having hundreds of antennas. This paper explores frequency division multiplexing as an approach for augmenting the baseband signals of multiple antenna channels such that a single ADC can sample a multitude of antennas in an array. The approach is equally applicable to both massive MIMO and mm-wave digital wireless arrays. An example design based on Xilinx RF SoC for combining 4 antenna channels at 28 GHz into a single ADC is provided. 
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  5. null (Ed.)