Micromechanical radial-contour mode disk resonator for a CMOS-MEMS oscillator

Abstract

Microelectromechanical system (MEMS) based on-chip resonators offer great potential for sensing and high frequency signal processing applications due to their exceptional features like small size, large frequency-quality factor product, integrability with CMOS ICs, low power consumption etc. In this work, micromachined polysilicon disk resonators exhibiting radial-contour mode vibrations have been designed, modeled and simulated. These resonators are optimized for a low motional resistance and hence, are ideal for use in radio frequency (RF) communication circuits like reference oscillators, mixers, filters etc. The design presented here is meant for achieving resonance frequencies of 107 MHz, 289 MHz and 453 MHz in the first three modes of vibration respectively. A low-noise CMOS oscillator circuit which can utilize this MEMS resonator instead of the traditional bulky off-chip quartz crystal resonators has also been proposed.