Model of scandium doped aluminum nitride based PMUT with high transmitting performance

A Piezoelectric Micromachined Ultrasonic Transducer (PMUT) model with high transmitting performance is established. 30% concentration scandium doped aluminum nitride film is used as piezoelectric material for the established MEMS model of PMUT. The expressions of PMUT vibration modes are given. The influence of PMUT structure on its transmitting sensitivity and receiving sensitivity is calculated. Through the frequency response of PMUT in medium, the influence of top electrode radius on resonant modes and transmitting parameters of PMUT is analyzed. Results show that (0,1) mode work in omni-directional mode, (0,2) mode operating in hypercardioid mode, and reasonable control of top electrode radius can be effective for designing target uses of PMUT.