Design and Non-Linear Modeling of a Wide Tuning Range Four-Plate MEMS Varactor with High Q-Factor for RF Application

摘要

In this study, a micro-electromechanical variable capacitor that can achieve a wide tuning range is presented. The mechanical behaviors such as squeezed film damping and modal analysis are investigated. Also, scattering parameters, electromagnetic properties, and linear and nonlinear circuit models are presented for MEMS varactors. The four-plate tunable capacitor has nominal capacitance of 0.055 pF, a Q-factor of 175 at 10 GHz, and a tuning range of 2.59:1. The presented four-plate MEMS varactor has a suspended plate with the ability of moving downward and upward in order to increase the tuning range. The results were obtained by using simulation software. For the mechanical analyses, FEM in COMSOL Multiphysics software was used, and Ansoft HFSS and Agilent ADS were used for the electromagnetic analyses.