A Compact MEMS SP4T Switch Operating in the Wide Terahertz Band

This paper presents a miniaturized microelectromechanical systems (MEMS) single-pole four-throw (SP4T) switch which shows high performance in the wide terahertz band. The method to solve the mismatch and transmission loss of single-pole-multi-throw MEMS switches at high frequencies is studied. Subsequently, the special dual-contact hybrid fixed-fixed beam is designed, and the compact symmetrical SP4T switch demonstrates the worst insertion loss of 1.8 dB. Among all the four switching states, the return loss of the input port is higher than 15 dB in 100–350 GHz despite the influence of the transition pad. The total circuit will be fabricated on a 50-µm fused quartz substrate using the surface micromachining process. Through-glass-via technology with a high aspect ratio is also required during this process. To the best of our knowledge, the proposed switch is expected to be the first reported on-chip MEMS SP4T switch working in the terahertz band. The advanced design will contribute to the potential terahertz devices in the future.