A Terahertz Tunable Waveguide Bandpass Filter Based on Bimorph Microactuators

Terahertz (THz) tunable filter plays a significant role for miniaturization and multifunction in application systems. The frequency of existing schemes for tunable waveguide filter can only reach up to the $W$ -band. The selection of tuning and assembly solution for THz band is significant and challenging. In this letter, we investigate the design of bimorph microactuator which uses microelectromechanical system (MEMS) technology. Based on this microactuator, we propose a THz tunable waveguide bandpass filter, whose center frequency can be tuned from 247 to 260 GHz. It is the first time to extend the center frequency of tunable waveguide bandpass filter to over 220 GHz while using MEMS bimorph microactuators to tune. The tuning ratio of the filter is 5.26%, and the measured insertion loss is better than 6 dB in the passband.