A 5.8-GHz continuous-wave (CW) radar was developed and integrated on a compact printed circuit board for near-hive monitoring of honeybees. It supported noninvasive detection of free-flying honeybees at 2 m and micro-Doppler extraction of bee wingbeat signatures at a closer range using both a double-balanced mixer and an in-phase/quadrature (IQ) mixer. The CW radar was integrated with machine learning to allow automated classification of incoming, outgoing, and hovering honeybees.

This MTT-S 70th anniversary article presents an in-depth overview of the Phase Change Materials (PCM) and metal insulator transition (MIT) materials for various RF circuits. The PCM and MIT-based RF devices are expected to bridge the gap between semiconductor and MEMS switches as they combine the low insertion loss performance of MEMS technology and the small size and reliability performance of semiconductor technology. 

This paper presents a design approach for dielectric slot waveguides fabricated in highly resistive silicon (HR-Si) designed for operation in the terahertz (THz) frequency range.

This letter shows a multiband RF filtering concept and a compact low-loss integration scheme for coaxial resonator-based multiband bandpass filters (BPFs). Size compactness is achieved by vertical stacking, subwavelength capacitively loaded coaxial resonators, and 3) monolithic integration enabled by additive manufacturing. Dual-band and triple-band BPFs operating at sub-6 GHz were designed, manufactured, and tested.

This article shows a low-loss compact platform that enables the integration of H-and E-plane rectangular waveguide subsystems enabled by 90° polarization rotation of rectangular waveguide sections on a silicon-micromachined chip. Prototypes are demonstrated in the 220-335 GHz frequency range.