Effect of environmental conditions and geometric parameters on the squeeze film damping in RF-MEMS switches

摘要

This paper presents a detailed analysis of squeeze film air damping effects on dynamic responses of RF-MEMS switches under varying environmental conditions, etch holes' configuration and air gap thickness values. The effect operating conditions like air pressure, temperature and humidity on the closing time of RF-MEMS switches is analyzed. The air pressure distribution beneath the top suspended plate of switches and corresponding damping parameters extraction, under varying conditions, is obtained using finite element method based modal projection technique. The extracted damping parameters are used in the subsequent coupled field electrostatic-structural dynamic analysis to analyze the effect of variation in environmental variations and geometric parameters on the closing time of RF-MEMS switches. The effect of change in etch holes' configuration on the damping parameters is obtained to be minimum while change in switch operating conditions and air gap thickness values have significant effect on the air damping value and closing time of switches.