End fire surface wave piezoelectric transducer

Abstract

An acoustic surface wave transducer characterized by a novel electrode coguration. A pair of electrode strips are positioned on the surface of a piezoelectric material, each of the strips having elongate fingers extending laterally towards one another. The fingers from the opposed electrode strips are aligned with one another, as opposed to the common interdigitated structure of the prior art. The fingers have a prescribed spacing from adjacent fingers as well as from opposed fingers. The prescribed configuration causes the electric field between corresponding fingers to peak at the points between the ends of the fingers which, in turn, causes high shear stresses to occur and be reinforced as the acoustic wave travels down the length of the material. The basic transducer generates a point source of acoustic waves. An extension of the basic embodiment utilizes an array of transducers having electrode pairs in the prescribed configuration and which are configured with respect to one another so as to render the point sources additive which yields a plane wave front.

Dependencies are inferred from the claim text.