Surface acoustic wave filter

摘要

A surface acoustic wave filter which comprises a substrate of piezoelectric material and a multistrip coupler. The multistrip coupler comprises a plurality of parallel conductive strips formed on the substrate; at least one input transducer is disposed on one side of the multistrip coupler, and at least one output transducer is disposed on the other side of the multistrip coupler. The surface acoustic wave filter is characterized in that a part of the middle portion of each of the conductive strips of the multistrip coupler is made of a photoconductive material.