Characterization and Modeling Method of Electrical and Mechanical Couplings for a MEMS Capacitive Gyroscope

In this paper, a novel characterization and modeling method is proposed to estimate and separate the electrical and mechanical couplings of a MEMS gyroscope. Firstly, the theoretical modeling of the electrical and mechanical couplings is conducted in detail for gyroscopes with ring diode readout circuits. Subsequently, the frequency responses of the electrical coupling, mechanical coupling, drive mode and sense mode, are simulated with Matlab software, which are applied to compared with those obtained by the sweep-frequency tests. Simulation and experimental results demonstrate that the frequency responses of the theoretical models accord with those measured by the sweep-frequency tests, indicating that the proposed models are accurate. Based on the proposed theoretical models, the mechanical coupling can be separated from the electrical coupling easily, providing a theoretical basis for electrical coupling suppression.