A dynamically mode-matched piezoelectrically transduced high-frequency flexural disk gyroscope

This paper presents, for the first time, the design, implementation, and characterization of a dynamically mode-matched high-frequency piezoelectrically transduced silicon disk gyroscope utilizing a unique pair of degenerate orthogonal in-plane flexural gyroscopic modes. To eliminate the need for submicron capacitive gaps and large DC polarization voltages that are needed for electrostatic tuning, a linear bidirectional frequency tuning scheme, compatible with all-piezoelectric transduction, is introduced to achieve dynamic mode-matching via active electromechanical feedback. A fabricated 4.34 MHz AlN-on-Silicon 1-mm-diameter solid disk gyroscope supported by a network of peripheral beams was frequency-tuned by 500 ppm (~2.2 kHz) and achieved a high measured sensitivity of 410 pA/°/s with an effective in-air quality factor of ~4000, corresponding to a large open-loop operation bandwidth of ~550 Hz under mode-matched conditions.