Development of Electrostatic Actuator, which enables the Stable Contact Resistance, Driven at Low Voltage

Abstract

The switches play an important role in making the multifunctional radio communication circuit and therefore, the high-performance microminiaturized high-frequency switches are urgently expected. RF-MEMS switch with mechanical switching structure is hoped to improve both high-frequency signal loss and isolation quality simultaneously and to provide better linearity on the performance and compatibility to silicon-based circuit elements. But considering the applications, such as cellular phone and wireless-LAN, lower driving voltage and smaller switch dimensions are required.
In order to solve these requirements, a novel electrostatic actuator with a unique structure of movable electrodes which enables the stable contact resistance is developed for RF-MEMS switches. This actuator has slits between the movable electrodes and the restoring spring. The electrostatic actuator with a movable electrode area of 0.5mm² was driven at low voltage of 9-11V. And no defect due to restoration shortage is observed during switching test up to 400million cycles.
In this paper, the results of mechanical design of the electrostatic actuator, the simulation, the experiments, and the reliability test are described