An Experimental Study of the Acoustic Field of a Single-Cell Piezoelectric Micromachined Ultrasound Transducer (PMUT)

TL;DR

This study investigates how packaging dimensions affect the acoustic radiation and directivity of single-cell PMUTs through simulations and experiments, aiding optimized design for specific applications.

Contribution

It provides a combined numerical and experimental analysis of packaging effects on PMUT acoustic fields, which was previously underexplored.

Findings

Packaging size significantly influences acoustic directivity.

Simulations accurately predict experimental results.

Design guidelines for PMUT packaging are proposed.

Abstract

Piezoelectric micromachined ultrasound transducers (PMUTs) have gained popularity in the past decade as acoustic transmitters and receivers. As these devices usually operate at resonance, they can deliver large output sound pressures with very low power consumption. This paper explores the influence of the transmitter's packaging on the radiated acoustic field in air. We run simplified axisymmetric numerical models to observe the change in the acoustic field and directivity with respect to the device's package dimensions. The simulations demonstrate a notable change in the directivity of transmitter based on the size of the baffle. Experimental measurements are carried out to validate the simulations, which prove useful in designing packages for transmitters to meet application specific requirements.