Modeling of an electrostatic torsional actuator: demonstrated with an RF MEMS switch

Abstract

We present an efficient methodology for setting up MEMS macromodels which are based on a physical device description and lead to tractable mathematical relations for the device operation. Since design and technology parameters are input parameters of the resulting model, our approach is in particular suited for design studies. In addition to the reduction in degrees of freedom, and hence, the reduced simulation time, macromodels can easily be coupled with the electronic circuitry, and thus the entire device can be simulated on system level. The model also allows for squeeze-film damping effects. Its practicality is demonstrated with reference to an electrostatic torsional RF-switch with low actuation voltage intended for the use in mobile communication. Furthermore, simulated and experimental data of the resonance modes are compared for validation and an improved design for faster switching is proposed and optimized.