A Novel MEMS Tunable Capacitor

A novel MEMS tunable capacitor with a high tuning ratio is presented in this paper. The novel tunable capacitor consists of two parallel electrodes, i.e., fixed and moving electrodes and six bi-directional electrostatic actuators, which are able to produce both attractive and repulsive force to drive the moving electrode. So the novel tunable capacitor is able to move in both directions, up and down, away form its static position and therefore achieve a large tuning ratio. Numerical simulations are used to verify the working principle of the novel tunable capacitor and predict that a tuning ratio of 3:1 can be achieved at a driving voltage of 16 volts.