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This paper presents a novel wideband single-pole-single-thru (SPST) switch fabricated by silicon micromachining and operates based on short-circuiting the dominant mode of the rectangular waveguide. The switch has a compact footprint, with a total size of 2×3.5×1.2 mm. The switching mechanism is implemented by a microelectromechanical (MEMS) actuator with an actuation voltage of ~40 V. It has two operating states of propagating and blocking mode. The measured return loss and insertion loss of the switch are 17 dB and 0.7-1.1 dB at 220-290 GHz in the propagating state. The presented switch also has tuning capability to operate with 20 dB return loss at 220-266 GHz. The measured isolation is also 28.5-32.5 dB in the blocking state at the same frequency span. QC 20230619

This paper describes a silicon micromachined radar frontend. The designed frontend system includes active and passive elements within a single silicon chip due to the high integration capability of silicon micromachining techniques. The active part includes a switching circuit, and the passive part consists of a beam steering and beam shaping network and a 2×8 array antenna. The frontend has two WR-3.4 standard waveguide ports, and each port can create two frequency steerable radiation patterns controlled by the switching circuit. The return loss of both ports is better than 10 dB at 220-267 GHz for both beam shapes. The size of the whole system is 14.3×20×1.2 mm, and it can be used in imaging, tracking, and surveillance applications. QC 20230612

This paper presents a silicon micromachined reconfigurable beam-steering frontend chip in which multiple components are integrated within a single silicon chip. The size o the whole frontend chip is 14.3×20×1.2 mm3. The signal path includes a novel switching circuit, a beam-steering network, two power-dividing networks, and a 2×8 array antenna. The presented frontend chip is able to create two frequency steerable beam-shapes. The switching circuit determines which beam shape to be radiated. The first beam-shape is a steerable broad fan-beam with reduced sidelobe level (SLL) in the H-plane, and the second is a steerable notched fan-beam. The measured SLL of the broad beam is better than 18.5 dB in the H-plane, and the measured notch depth is better than 24 dB in the E-plane pattern. Both radiation patterns can be steered by frequency and move from -20 degrees at 238 GHz to +20 degrees at 248 GHz.The measured return loss of the fabricated device is better than 15 dB at 220-265 GHz, which is equal to almost 18.6 % fractional bandwidth. QC 20230630

This paper presents a novel single-pole-single-throw wideband microelectromechanical switch circuit operating in the 220 to 290 GHz frequency band. The switching operation is based on short-circuiting the dominant TE10 mode of the rectangular waveguide by micro-electromechanically reconfigurable surfaces. The improved performance of this switch circuit comes from utilizing two such reconfigurable surfaces and taking advantage of the interference between them to achieve improved RF performance, in particular in terms of return loss and isolation. The switch has a compact design with dimensions of 2×3.5×1.2 mm3. Due to its axial port arrangement, it can be mounted directly between two standard waveguide flanges. The insertion loss, measured between the two standard waveguide flange interfaces and including all internal circuit routing and E-plane bends, is between 0.7-1.2 dB. The measured return loss is better than 17 dB in the entire frequency band of 220 to 290 GHz. Reference waveguide measurements of the same prototype fabrication run showed that 0.2-0.5 dB of the measured insertion loss comes from the waveguide itself. The measured isolation of the switch is very uniform in the whole 220-290 GHz waveguide band and between 28.5-32.5 dB. The measured fractional bandwidth of 27.5% has been achieved, which is almost equal to a full waveguide band performance. QC 20230612