Surface acoustic wave device

Abstract

A surface acoustic wave device comprises a substrate and a set of interdigital electrodes disposed thereon and spaced apart. One interdigital electrode is divided along the propagating direction of the surface acoustic wave into a plurality of portion interdigital electrodes which are electrically connected in series. The electrode pattern of the one interdigital electrode is formed asymmetrically such that the static capacitances of at least two adjacent portion electrodes thereof are different from each other, preferably in such a manner that when the device is installed, the total effective static capacitances of the two adjacent portion electrodes will be substantially equal. The static capacitance of the portion electrode having a comb shaped electrode thereof which is to be grounded is selected to be smaller than that of the other portion electrode. In case of the portion electrode not having a comb shaped electrode grounded, the static capacitance of the portion electrode closer to the other interdigital electrode is selected to be smaller than of the other portion electrode.

Dependencies are inferred from the claim text.