Nonlinearity tuning and its effects on the performance of a MEMS gyroscope

A three-fold symmetric SOI-MEMS gyroscope having parasitic softening nonlinearity from the drive comb and frequency tune fingers is successfully linearized through the use of shaped comb fingers that introduce a tuned cubic hardening compensation. The nonlinearity compensated gyroscope achieves high drive displacement (>10μm) while maintaining linear magnitude and phase frequency responses. The proposed tuning method also minimizes the amplitude-frequency (A-f) effects on the drive mode. Cancelling the drive nonlinearities leads to a better bias instability compared to the high displacement with nonlinear characteristics.