MEMS tunable capacitor with wide tuning range using multiple voltage sources

This paper presents a MEMS surface micro-machined varactor. The dynamic range of this class of varactors is governed by pull-in instability which is ideally one-third of the initial gap between the two electrodes. This paper presents a simple T varactor, whose pull-in stability and hence its dynamic range are increased by applying two independent voltage sources. We introduce an electromechanical model for the proposed structure, and a full analytic solution to the attached pull in problem. Our varactor has capacitance ratio of 2.43:1.