SURFACE ACOUSTIC WAVE CONVERTER AND ACOUSTIC WAVE FILTER USING THE SAME

摘要

In order to provide a transducer suitable for an anisotropic substrate having the NSPUDT property, on the anisotropic piezoelectric substrate being cut to have the NSPUDT property, there is formed a transducer structure having an exciting electrode structure (21) and a reflector structure (22). When lambda is a wavelength of a fundamental surface acoustic wave, said exciting electrode structure (21) includes a positive electrode (23) having a plurality of electrode fingers arranged at a pitch lambda and a negative electrode (24) having at least one electrode finger interdigitally arranged between said electrode fingers of the positive electrode with a center distance of lambda /2. The reflector transducer (22) includes a plurality of electrode fingers arranged with a center distance of lambda /2, and a distance Lg between said exciting electrode structure (21) and the reflector structure (22) is set to Lg = (2n+1) lambda /4 (n being a positive integer). <IMAGE>