V-band bandpass filter with continuously variable centre frequency

A second-order bandpass filter (BPF) with continuously variable centre frequency tuning is presented in this article. Evanescent-mode cavity resonators with variable capacitive loadings are used as tuning elements. Tuning is achieved by means of micro-electromechanical-systems (MEMS)-actuated highly conductive rigid fingers that feature an out-of-plane deflection. For an applied DC bias voltage be...