Abstract
In this work, we demonstrate a simple and effective method for reducing the membrane ring-down time and suppressing the output interferences caused by nonlinearity to benefit axial resolution for piezoelectric micromachined ultrasonic transducers (PMUTs). This method breaks the dead zone limitation of PMUTs through a phase shift of driving waveform with a window function. The proposed phase shift waveform with window function can effectively minimize the ring-down time on the transmitting node (TX) and thus reduce the dead zone region in a pulse-echo measurement system. In addition, the unwanted ripples and interference signals of the receiving output (RX) caused by nonlinear behaviors of PMUTs, thereby resulting in worse axial resolution, can be significantly suppressed on the receiving node (RX). This technique shows a great performance enhancement for PMUTs with high accuracy and axial resolution during measurement.