MEMS-based piezoelectric BAW resonator based on out-of-plane degenerate mode for micro angular detector

A novel microelectromechanical piezoelectric concentrated-mass bulk acoustic wave (BAW) resonator based on out-of-plane degenerate mode is proposed for detecting micro angles. A PZT resonator with a concentrated-mass is designed to enhance the driving and sensing efficiency. The device combines the bulk acoustic wave drive/sense with a rocking concentrated mass to increase the resonant frequency, the signal quality and the resolution of the sensor. A 10 × 10 mm device has been fabricated and assembled by the microelectromechanical system process and the traditional mechanical process. The test results measured by the impedance analyser in air show that the resonant frequency and the quality factor of this device are about 174 kHz and 110, respectively. Moreover, the frequency split is only about 200Hz without any tuning methods.