MEMS-Switchable Coupled Resonator Microwave Bandpass Filters

Two microelectromechanical systems switchable microwave bandpass filters are presented. Both filters are compact fourth-order symmetrically coupled filters-the first is designed with bridge capacitive switches, while the second uses cantilever capacitive switches. The bridge-switched filter tunes from 21.6 to 16.85 GHz with insertion losses of 0.9 and 1.0 dB, respectively. The cantilever-switched filter tunes from 21.85 to 15.15 GHz and has insertion losses of 0.6 and 1.0 dB, respectively. Both the bridge and cantilever capacitive switches are electrostatically actuated using dc voltages of 70 and 55 V, applied through high-resistivity chrome-silicide lines. The reported filters show state-of-the-art performance in insertion loss and frequency tuning characteristics.