Ku Band High-Q Tunable Surface-Mounted Cavity Resonator Using RF MEMS Varactors

This paper presents a 14 GHz high-Q (quality factor) tunable resonator using microelectromechanical system (MEMS) varactors. A brass surface mountable cavity has been bonded on a fused silica wafer on which are processed three 1.1 mm long MEMS varactors. Their location has been optimized in order to obtain a wide frequency shift, when the cantilevers are actuated on the substrate. 15% tuning range from 11.9 GHz to 14.2 GHz has been obtained with a continuous shift from 11.9 GHz to 13.6 GHz. Measurements result in an average unloaded quality factor (
Qu
) of 480 over the operating frequency band.