A High-Performance Square pMUT for Range-finder

A rangefinder based on an AIN piezoelectric micromachined ultrasound transducer (pMUT) is presented to localize targets up to 10 cm using pulse-echo (PE) mode. An experimental set-up has been described and implemented to characterize two kinds of pMUTs: square pMUT and circular pMUT. Compared to the traditional circular pMUT with top electrode laying on the center part, the square pMUT with outer frame-like electrode shows better performance in receiving ultrasonic waves. Working at the same frequency, the square pMUT saves 11.2% area and can achieve higher fill factor in array. Both pMUTs are tested at the frequency of 400 kHz in air.