Surface acoustic wave apparatus

摘要

A surface acoustic wave apparatus has a configuration by which the spurious of the higher-order transverse modes is suppressed and a SAW excitation intensity distribution is not changed in the propagation direction. The surface acoustic wave apparatus has at least one interdigital transducer; a region with the plurality of interleaved comb-shaped electrodes is formed with two regions which are a first overlapping region and a second overlapping region with overlapping-lengths weighted along a propagation direction of a surface acoustic wave; the first overlapping region and the second overlapping region are in contact or overlapped in a direction vertical to the propagation direction of the surface acoustic wave; and in either the first or the second overlapping region, an overlapping-length weighting envelope curve has at least two or more changing points in the propagation direction of the surface acoustic wave.