Bulk acoustic wave gyroscope
AssigneeGeorgia Tech Research Corporation
InventorsFarrokh Ayazi, Houri Johari
Life of this patent
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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.
Claims31
A gyroscope, comprising:
- a bulk acoustic resonator;
- at least one first electrode coupled to the bulk acoustic resonator, the at least one first electrode being positioned to excite vibration of the bulk acoustic resonator in a first bulk acoustic wave mode;
- and
- at least one second electrode coupled to the bulk acoustic resonator, the at least one second electrode being positioned to detect vibration of the bulk acoustic resonator in a second bulk acoustic wave mode, the first and second bulk acoustic wave modes being degenerate.
A gyroscope, comprising:
- a microelectromechanical resonator having a resonant frequency of 1 MHz or higher;
- at least one first electrode coupled to the microelectromechanical resonator, the at least one first electrode being positioned to excite vibration of the microelectromechanical resonator in a first mode;
- and
- at least one second electrode coupled to the microelectromechanical resonator, the at least one second electrode being positioned to detect vibration of the microelectromechanical resonator in a second mode.
Dependencies are inferred from the claim text.