Bulk Acoustic Wave Gyroscope

Abstract

Capacitive bulk acoustic wave x, y and z-axes gyroscopes implemented on (100) and (111) silicon substrates are disclosed. Exemplary gyroscopes comprise a handle substrate, a bulk acoustic wave resonator element supported by the handle substrate, and a plurality of electrodes surrounding and separated from the resonator element by very small capacitive gaps. The electrodes can excite and detect at least two degenerate bulk acoustic wave resonant modes in the resonator. Advantages include reduced size; higher Q, which improves noise and bias stability; larger bandwidth, and improved shock resistance. In addition, the high Q is maintained in atmospheric or near-atmospheric pressure which reduces the cost and complexity of the wafer-scale packaging of the gyroscope.