Phase noise analysis of the Frequency Tracking Oscillator

Abstract

The Frequency Tracking Oscillator (FTO) is being more and more used to drive vibrating MEMS sensors resonators (inertial sensors and mass sensors) because of its ability to control the phase shift over the resonator and thus to track the resonance frequency. The goal of this work is to study the FTO phase noise that determines the sensor resolution. First a phase noise model of the FTO is presented, then simulations are performed to quantify the impact of oscillator elements phase noises on the output phase noise. Finally model simulations are compared to experimental phase noise measurements.