Surface acoustic wave device improved in convolution efficiency, receiver using it, communication system using it, and method for producing surface acoustic wave device improved in convoluting efficiency

摘要

A surface acoustic wave device includes a substrate having piezoelectricity, at least two input electrodes, provided on the substrate, for exciting first and second surface acoustic waves, and an output electrode for taking a convolution signal of the two surface acoustic waves out. The substrate has a roughness configuration on a back face thereof and a maximum depth of the roughness configuration is not less than a wavelength of bulk waves of convolution output taken out of the output electrode.