Influence of RF signal power on tunable MEMS passive components

Abstract

MEMS structures are usually sensitive to the electrostatic or magnetic forces, but the influence of the force created by the RF signal going through them is rarely considered. In the case of MEMS tunable components, like microcapacitors or microinductors, the consequences of high RF power levels on performances are to be quantified. Two microcapacitors systems are studied: one-gap with RF signal and actuation voltage on same electrodes, and two-gaps with RF signal separated from actuation. Computational results show great influence of power on pull-in, even for quite low power levels, for both MEMS capacitor structures. Then, a similar approach is proposed for tunable microinductors, considering the influence of RF power on the Laplace force: a simple geometry with two coupled loops is studied, and the influence of power appears again very important.