Monolithic mosaic transducer utilizing trapped energy modes

A major difficulty In the fabrication of a large mosaic transducer is the achievement of adequate acoustic isolation of the small transducer elements making up the array. In order to obtain the isolation some workers have combined completely separate individual transducer elements [l] while others have used a large piezoelectric plate with grooves [2, 3]. The latter procedure is somewhat less cumbersome but still difficult for very small element sizes. Recently attention has been directed towards acoustic isolation schemes which do not require grooves. Some of these techniques involve matched terminator backing for the plate [k]. In this way the internal plate reflections that produce coupling are reduced.