A Wafer-Level Vacuum-Packaged MEMS Quadruple Mass Gyroscope Operated in Mode-Split and Open-Loop Detection

Abstract

This letter proposes a wafer-level vacuum-packaged micro - electro - mechanical systems (MEMS) quadruple mass gyroscope (QMG) based on the classical QMG architecture. The design incorporates several innovations to enhance performance in open-loop and mode-split operation modes. The proposed QMG employs variable-area comb electrodes to improve driving electrostatic nonlinearities and sensing nonlinearities. Quadrature errors are reduced through electrostatic negative stiffness using quadrature electrodes on proof masses. Wafer-level vacuum packaging achieves a high drive mode Q-factor of 1.06 million, enabling a low ac driving voltage of 4.7 mV, thereby effectively suppressing the feedthrough interference. The use of numerous sensing combs and a frequency and damping regulator reduces the sense mode Q-factor to 0.11 million, enhancing environmental interference resistance. In addition, the numerous sensing combs further enhance the open-loop scale factor. Leveraging these innovative designs, the QMG achieves a bias instability of 0.54°/h at a frequency split of 70 Hz, an angle random walkof 0.55°/√h, a dynamic range of ±300°/s, and a theoretical bandwidth of 37.8 Hz. These characteristics demonstrate that the proposed QMG achieves satisfactory performance in frequency-split and open-loop modes.