ABSTRACT
This chapter presents an overview of the high-frequency bulk acoustic wave (BAW) gyroscopes. The BAW gyroscopes should be fabricated in a high-aspect-ratio process. Owing to the high frequency of operation, large electrostatic forces should be applied to enable excitation of the device. The sensitivity of a gyroscope is determined by the capacitance change at the sense electrodes, originating from the sense mode excitation due to the Coriolis force. In BAW gyroscopes, single-crystal silicon disk gyroscopes are designed to operate in their degenerate elliptic bulk acoustic modes with frequencies in the range 1–20 MHz. This enhances the operational bandwidth of the gyroscope in the mode-matched condition compared to low-frequency flexuralmode gyroscopes. A number of fabricated silicon disk gyroscopes were fabricated and characterized on a variety of thick silicon-on-insulator substrates. Dynamic range, another important performance parameter in gyroscopes, refers to the range of input rates over which the output is detectable.
