Rectangular PMUT Phased Array with High Fill-Factor and High Sound Pressure Level

Ultrasonic imaging is essential in various fields, demanding sufficient output power to achieve deep penetration. In piezoelectric micromachined ultrasonic transducer (PMUT) arrays, the fill-factor, or the ratio of active area to total area, is critical in determining the output power, influencing their efficiency and sensitivity of the system. While circular PMUT arrays, commonly reported in the literature, typically have a fill-factor below 50%, this paper introduces a novel rectangular PZT-based PMUT array with a fill-factor exceeding 70%. This higher fill-factor results in a high sound pressure level (SPL) output of 1400 dB/V at surface, making this array ideal for ultrasonic phased array imaging applications.