Micro electro-mechanical system device with piezoelectric thin film actuator

Abstract

A radio frequency (RF) micro electro-mechanical system (MEMS) device and method of making same are provided, the device including an RF circuit substrate and an RF conducting path disposed on the RF circuit substrate, a piezoelectric thin film actuator, and a conducting path electrode. The piezoelectric thin film actuator has a proximal end that is fixed relative to the RF circuit substrate and a cantilever end that is spaced from the RF circuit substrate. The conducting path electrode is disposed on the cantilever end of the piezoelectric thin film actuator. The cantilever end of the piezoelectric thin film actuator is movable between a first position whereat the conducting path electrode is spaced from the RF path electrode and a second position whereat the conducting path electrode is spaced from the RF path electrode a second distance, wherein the second distance is less than the first distance. The RF MEMS device is particularly useful as a tunable capacitor. The RF MEMS device requires lower operating voltage, and provides variable RF tuning capacity, fewer stiction problems, simplified fabrication, and an improved switching time.