High-frequency capacitive disk gyroscopes in (100) and (111) silicon

This paper reports on the design and implementation of capacitive bulk acoustic wave (BAW) disk gyroscopes in single crystal silicon. The capacitive BAW disk gyroscopes are stationary devices operating in their degenerative MHz- frequency bulk acoustic modes with very small vibration amplitudes (<20 nm). They can achieve very high quality factors (Q) in moderate vacuum and even under atmospheric pressure, which substantially simplifies their wafer-level packaging. In addition, their small operating voltages simplify the interface circuit design and implementation in standard CMOS.