Closed-Loop Compensation of the Quadrature Error in MEMS Vibratory Gyroscopes

In this paper, a simple but effective method for compensation of the quadrature error in MEMS vibratory gyroscope is provided. The proposed method does not require any change in the sensor structure, or additional circuit in the feedback path. The mathematical relations of the proposed feedback readout system were analyzed and the proposed solution assures good rejection capabilities. Based on the simulation results, the proposed method increases the dynamic range of the readout circuit by about 19 dB for the quadrature error with 10 times higher amplitude than the Coriolis signal. Furthermore, the feedback path reduces the effect of the 1 degree LO mixer phase error in the output path by about 95%, which causes our system to be less sensitive to this error. In addition, the 2nd harmonic component at the output of the proposed feedback readout is much lower than that of the conventional readout. As a result, proposed feedback readout can relax the requirement of the output low pass filter. In addition, the 2nd harmonic component at the output of the proposed feedback readout is much lower than that of the conventional readout. As a result, proposed feedback readout can relax the requirement of the output low pass filter.