Vibration Sensitivity of MEMS Tuning Fork Gyroscopes

MEMS tuning fork gyroscopes (TFGs) are known to be relatively immune to vibrations due to their differential operation and common-mode rejection. However, even a perfectly-matched TFG cannot completely eliminate vibrations due to vibration-induced asymmetry and nonlinearity. We select two commonly used gyroscope structures and analyze their vibration characteristics. Both structures employ decoupled sense and drive masses with "Type-A" having an anchored sense mass and "Type-B" having an anchored drive mass. To understand the effects of vibration on these two structures, we performed nonlinear dynamic simulations using MATLAB and SIMULINK. The results show that Type-B structures are insensitive to vibrations (>99% reduction) when compared to Type-A structures. In addition, the simulations reveal the dominant vibration characteristics for each structure.