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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 30GHz for 310fF.

Radio frequency applications for microelectromechanical systems are reviewed, from a performance and fabrication prospective. The state of art in RF MEMS devices is discussed, focusing on switches, inductors, varactors, filters, phase shifters and antennas.

MEMS based microwave phase shifter designs are presented which give a continuously tunable, low loss voltage controlled phase shift. The device reported here offers a significant improvement over the circuits previously published. Measurements indicate that a 260 degree phase shift per centimeter is obtained at 30GHz, with a 90 degree phase shift per dB loss. This presents state of the art performance in analog MEMS tunable phase shifters.