ABSTRACT
We describe 2D/3D model studies of resonance and radiation characteristics of diced matching layers for ultrasound transducers. Calculations are done with PZFlex, a time-domain, finite element, electromechanical code. Continuous, thin film, quarter-wave matching layers have, of course, been used routinely at optical interfaces for most of this century. A similar approach is often vital to achieving the acoustic performance required of ultrasound imaging transducers.
However, the ultrasound problem is complicated by lateral propagation in the layer and crosstalk between transducer elements. This necessitates dicing the continuous layer into discrete resonators on the piezoelectric element(s), whence, crosstalk is minimized, but sometimes at the expense of anomalous local modes and compromised radiation patterns. To better understand multi-dimensional diced matching layer dynamics, a single, solid piezoceramic element and a multi-element composite are modeled. We examine beam pressure and mode shapes and include comparisons with experimental composite data and a coupled-mode design curve.