Programmable synchronization enhanced MEMS resonant accelerometer
Liu Xu, Shudong Wang, Zhuangde Jiang, Xueyong Wei
Abstract
Acceleration measurement is of great significance due to its extensive applications in military/industrial fields. In recent years, scientists have been pursuing methods to improve the performance of accelerometers, particularly through seeking new sensing mechanisms. Herein, we present a synchronized oscillator-based enhancement approach to realize a fivefold resolution improvement of a microelectromechanical resonant accelerometer. Through the unidirectional electrical coupling method, we achieved synchronization of the sensing oscillator of the microelectromechanical resonant accelerometer and an external reading oscillator, which remarkably enhanced the stability of the oscillation system to 19.4 ppb and the resolution of the accelerometer to 1.91 μg. In addition, the narrow synchronization bandwidth of conventional synchronized oscillators was discussed, and hence, we propose a novel frequency automatic tracking system to expand the synchronization bandwidth from 113 to 1246 Hz, which covers the full acceleration measurement range of ±1 g. For the first time, we utilized a unidirectional electrical synchronization mechanism to improve the resolution of resonant sensors. Our comprehensive scheme provides a general and powerful solution for performance enhancement of any microelectromechanical system (MEMS) resonant sensor, thereby enabling a wide spectrum of applications.