A micromachined gyroscope with piezoresistance for both high performance Coriolis-effect detection and torsional vibration monitoring

A micromachined vibrating gyroscope with a novel piezoresistive scheme is designed, fabricated and tested. A piezoresistive sensing method for Coriolis-acceleration detection is used with both high sensitivity and high resonant frequency. A four-terminal piezoresistive element is used to monitor and stabilize the vibration amplitude of the driving mode through a feedback loop. With the same loop, temperature drift of the gyro´s piezoresistive output can be on-chip compensated effectively. The gyro performance is measured, with the following results: resonance frequency in detection mode is 989 Hz; angular rate measurement range is ± 300°/s; noise-limited angular rate resolution is 0.33°/s.