| Reconfigurable radio frequency (RF)/microwave components are needed to realize high performance multi-band/multi-mode radios. Such tunable components can potentially reduce the system complexity. However, careful attention must be given to their design in order to satisfy strict system level requirements. The objective of this dissertation is to develop tunable technologies for high-Qu preselect filters.;The first part of the dissertation focuses on deploying electrostatic fringing-field actuated (EFFA) MEMS in tunable evanescent-mode cavity-based resonators. EFFA MEMS tuners provide analog frequency coverage that is not limited by the conventional pull-in instability. Furthermore, total lack of dielectric layers and no overlap between the pull-down electrode and movable beams significantly enhances the device robustness. The modeling, design, and experimental validation of EFFA MEMS is presented and discussed. A tunable resonator based on EFFA MEMS with a Qu of 280–515 from 12.5–15.5 GHz, tuning speed of 145–190 microseconds, and vibration-induced sideband amplitude of -40 dBc at 15g is demonstrated.;The second half of the dissertation addresses the electromechanical performance of MEMS-based tunable resonators. A tunable resonator is developed based on parallel-plate field MEMS tuners demonstrating a Qu of 600-1100 from 10.5–13 GHz and a tuning speed of 84–112 microseconds. Finally, an all-silicon tunable resonator based on identical tuners demonstrates a Qu of 500–735 (75-85 % of simulation) from 15.2–17.8 GHz and tuning speeds of less than 20 microseconds. |
