On Extending Signal-to-Noise Ratio of Resonators for a MEMS Resonant Accelerometers Using Nonlinearity Compensation

In this work, the relationship between nonlinear effects and the signal-to-noise ratio of a resonator is analyzed and the impact of reducing nonlinear effects of the resonator on the performance of a resonant accelerometer is investigated. A theoretical framework is formulated to evaluate the dynamic range of the double clamped-clamped resonator. A reduction of the mechanical nonlinearity is achieved through an external electrostatic force, resulting in an enhancement of the dynamic range from 93.8 dB to 132.6 dB. Experimental findings indicate the nonlinear coefficient is reduced to 2.2% compared to an approach without nonlinearity compensation. The nonlinearity compensation demonstrates a 12.8 dB improvement in the signal-to-noise ratio of the resonator, leading to a 5.5-fold increase in resolution of the accelerometer and an extension of the dynamic range by 15 dB. The proposed technique enables the performance of resonant sensors to be further optimized.