High-Q MEMS-reconfigurable waveguide filters

This paper presents an innovative concept for the design of MEMS-reconfigurable bandpass filters with very high Q-factor. MEMS switches are arranged at one or both sides of a TE₁₀₁ mode cavity so as to provide an equivalent reconfigurable inner waveguide wall. The effective width of the cavity can be changed by activating the MEMS switches, so as to control the cavity resonant frequency. The proposed method yields higher Q-factors with respect to other approaches involving ridged or conductor-loaded cavities. Preliminary measurements of a 10 GHz 4^th order bandpass filter show a 400 MHz frequency shift with a Q-factor above 900.