Phase Noise Optimization of MEMS Resonant Accelerometer Based on AC Polarization

Abstract

Microelectromechanical system (MEMS) resonant accelerometers have attracted significant interest for practical application owing to their high sensitivity and quasi-digital output. One approach to improve the long-term stability and resolution of the resonant accelerometer is to utilize AC polarization. However, there is a lack of systematic studies on the phase noise of the AC polarization resonant accelerometer. In this paper, we present the phase noise model of AC polarization resonant oscillator, especially the influence of the frequency of the AC polarization on the phase noise, which covers the <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$1\!/ \!f^{0}$ </tex-math></inline-formula> phase noise, <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$1\!/ \!f^{2}$ </tex-math></inline-formula> phase noise, and <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$1\!/ \!f^{3}$ </tex-math></inline-formula> phase noise. The optimization of the frequency of AC polarization signal to phase noise ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$1\!/ \!f^{0}$ </tex-math></inline-formula> phase noise and <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$1\!/ \!f^{2}$ </tex-math></inline-formula> phase noise) is investigated, and numerical simulation and experimental measurement are performed on a prototype of AC polarization resonant oscillator to validate this model. The phase noise model can be used to guide the optimization of high-performance resonant sensors utilizing AC polarization. [2022-0169]