A sub-0.1°/h bias-instability MEMS gyroscope using resonant constant-frequency driving technique

The work illustrates a resonant constant-frequency (RCF) driving technique used in a MEMS gyroscope which has linear frequency-tuning triangular capacitors. Differing from that conventional driving technique where the gyroscope excitation frequency is time-varying, the RCF strategy assures that the excitation frequency and resonant frequency are equal and constant in the gyroscope drive mode by means of frequency-tuning feedback. As a result, RCF can eliminate effects of excitation-frequency instability and drift on gyroscope output performance. Combining RCF with real-time automatic mode-matching, the tested gyroscope with sense-mode quality factor of 26.75k has achieved bias instability of 0.09 °/h and angle random walk of 0.0087°/√h.