Patent ID: 8791773

Claim:
A surface acoustic wave filter, comprising: a plurality of series-connected type IDT electrodes each comprising a first IDT electrode which comprises an input/output electrode comprising a plurality of first electrode fingers, and a first floating electrode with a floating state electrically comprising a plurality of second electrode fingers, and a second IDT electrode which comprises a ground electrode comprising a plurality of third electrode fingers, and a second floating electrode with a floating state electrically comprising a plurality of fourth electrode fingers and being connected to the first floating electrode, wherein the plurality of series-connected type IDT electrodes comprises a first series-connected type IDT electrode and a second series-connected type IDT electrode which is adjacent to the first series-connected type IDT electrode, the first IDT electrode of the first series-connected type IDT electrode and the second IDT electrode of the second series-connected type IDT electrode being located next to each other, at least one of the plurality of first electrode fingers of the first series-connected type IDT electrode is located facing the second series-connected type IDT electrode, at least one of the plurality of third electrode fingers of the first series-connected type IDT electrode is located facing the second series-connected type IDT electrode, at least one of the plurality of first electrode fingers of the second series-connected type IDT electrode is located facing the first series-connected type IDT electrode, and at least one of the plurality of third electrode fingers of the second series-connected type IDT electrode is located facing the first series-connected type IDT electrode.