A high-accuracy differential resonant pressure sensor with two similar resonators is proposed using the linear fitting method to guarantee its output linearity without polynomial compensation. Results reveal that the nonlinearity of the differential resonant pressure sensor is largely dependent on the tensile/compressive sensor pressure–stress ratio c when two similar resonators are used separately as compressive and tensile elements. Nonlinearity decreases sharply with an appropriate ratio c. A theoretical model is proposed to obtain minimal nonlinearity and shows satisfactory agreement with the simulation results. The impact factors of ratio c are analyzed to facilitate adjustments with the designed value. Moreover, micromachining methods are used to fabricate sensing chips. Experiment results show that the nonlinearity and measurement sensitivity of the proposed differential resonant pressure sensor are 0.02% FS and 35.5 Hz kPa⁻¹ with the linear fitting method in a pressure range of 0–200 kPaA and temperature range of −40 C to +40 C. The differential linear fitting method largely decreases compensation complexity without polynomial fitting for high-precision pressure measurement.

提出了一种采用线性拟合方法的具有两个相似谐振器的高精度差分谐振压力传感器，以确保其输出线性而无需多项式补偿。结果表明，当两个类似的谐振器分别用作压缩和拉伸元件时，差分谐振压力传感器的非线性很大程度上取决于拉伸/压缩传感器的压力-应力比c。非线性以适当的比率c急剧减小。提出了一个理论模型来获得最小的非线性，并与仿真结果显示出令人满意的一致性。比率c的影响因素进行分析以利于根据设计值进行调整。此外，微加工方法用于制造感测芯片。实验结果表明，在0–200 kPaA的压力范围和−40 C至+40的温度范围内，采用线性拟合方法，所提出的差分谐振压力传感器的非线性和测量灵敏度分别为0.02％FS和35.5 Hz kPa ^-1 C.差分线性拟合方法可在不进行多项式拟合的情况下大幅降低补偿复杂性，从而可进行高精度压力测量。