A Low-Voltage Wideband AlN-on-Si Gyroscope With Sub 10-DPH Bias Instability Mode Matched Using Laser Trimming

Abstract

This paper reports on the characterization of a high frequency (3MHz) aluminum nitride (AlN) on silicon resonant gyroscope mode-matched using laser trimming and operated using a multi-coefficient eigenmode technique. The annulus gyroscope uses a pair of bulk-acoustic wave (BAW) in-plane bending modes with strong piezoelectric coupling, showing a moderate $Q$ ~10,000 for expanding the open-loop operational bandwidth to 150Hz. A non-iterative trimming algorithm is implemented to match the frequency in a single pass, and an engineered electrodes layout enables multi-coefficient eigenmode operation to create virtual driving/readout vectors matching the actual non-ideal mode shape to reduce the quadrature error and bias instability.