High frequency XYZ-axis single-disk silicon gyroscope

This paper reports on the design and implementation of a single-disk capacitive gyroscope capable of sensing rotation rates around x, y and z axes. A single crystal silicon disk is operated in its appropriate in-plane and out-of-plane modes in the MHz frequency range to sense the z-axis and xy-axis rotation rates, respectively. Utilizing a single disk for measuring rate around all three axes minimizes the form factor compared to approaches using three separate proof masses. Due to high frequency operation, both in-plane and out-of plane modes can achieve high quality factors (Q) in moderate vacuum (1-10Torr), facilitating the wafer-level encapsulation of the device. In addition, the device bandwidth, in the range of 20 to 50 Hz, is suitable for the relatively fast response time requirements of consumer electronics applications.