Patent ID: 7671705

Claim:
A surface acoustic wave filter comprising: an interdigital transducer disposed on a piezo-electric substrate, said interdigital transducer including comb-shaped electrodes having a plurality of interdigital electrodes arranged in a propagation direction of surface acoustic waves and bus bars for connecting these interdigital electrodes, arranged in opposition, said interdigital electrodes being so overlapped as to insert with one another, wherein said interdigital transducer includes, one or more branch electrodes branched from at least one of said interdigital electrodes and positioned in a non-overlap zone between an overlap zone at which said interdigital electrodes overlap and a bus bar, said one or more branch electrodes includes a branch electrode body extending in a direction substantially orthogonal to the propagation direction of surface acoustic waves, and said one or more branch electrodes has a leading end electrically opened.