Electrostatically-tunable analog RF MEMS varactors with measured capacitance range of 300%

This paper reports on the design, fabrication, and testing of a novel analog MEMS varactor with measured tuning range of 300%. The proposed electrostatically actuated varactor is based on a parallel-plate approach and is best suited for microwave/millimeter-wave applications. The measured capacitance values are in the range of 40-160 fF and are achieved with DC voltages of 20-34 V. The proposed varactor has the additional advantages of very high resonant frequency (its series measured parasitic inductance is 9 pH) and high quality factor (higher than 80 at 40 GHz).