Wideband Micromachined Transitions for MEMS Tunable High-Q Filters

Two types of micromachined RF transitions for interconnecting coplanar waveguides (CPW) on silicon to microstrip lines suspended on membranes are presented. These transitions are a critical component for developing MEMS tunable high-Q filters for Ka and U-band applications. Their fabrication is based on a DRIE etching process which provides excellent control of the size and shape of the etched structure, therefore excellent control of the transition's RF performance. The presented transitions have sufficient bandwidth for covering the 35-55 GHz range within which the MEMS tunable filters is operating