Broadband tunable acoustic impedance matching using gradient-distributed piezoelectric structure

Abstract

In this paper, we propose a broadband tunable acoustic matching layer (BTAML) comprising an array of piezoelectric elements with non-uniform gradient shunt circuits (NGSCs). The effective impedance of the BTAML can be controlled in real time by regulating the parameters of NGSCs. The theoretical results demonstrate that BTAML is capable of adjusting impedance from 1.5 to 20 MRayl and has a broad bandwidth compared with the traditional matching layer. Furthermore, we experimentally verified the acoustic transmission property of the BTAML, and good agreement was achieved with numerical simulations. The approach can significantly promote research on tunable acoustic matching and offer effective impedance matching layers with a broad bandwidth in industrial applications.