Performance and operation of stressed dual gap RF MEMS varactors

The design, fabrication and measurement of a continuously tunable RF MEMS capacitor is described. The capacitor’s dual gap height architecture allows for electrostatic tuning with low resistive loss and a large tuning range. A new dual tuning scheme is introduced for use with two voltage sources. This dual tuning, coupled with a stress-induced bridge, is used to reach further device tuning. Measurements indicate a continuously tunable capacitance range of 6.2:1 with a quality factor over 50 at 30 GHz for 310 fF.