Patent ID: 8289107

Claim:
An acoustic wave device comprising: a piezoelectric material; a first interdigital transducer electrode disposed on the piezoelectric material; second and third interdigital transducer electrodes disposed on the piezoelectric material and at both edges in acoustic wave propagation directions, of the first interdigital transducer electrode; and first and second reflectors disposed on the piezoelectric material and at edges in the acoustic wave propagation directions, of the second and third interdigital transducer electrodes; wherein each of any two interdigital transducer electrodes adjacent to each other in the acoustic wave propagation directions, of the first to third interdigital transducer electrodes, includes a narrower-pitch electrode finger portion at an edge thereof adjacent to the other interdigital transducer electrode, the narrower-pitch electrode finger portion having an electrode finger cycle shorter than a cycle of the other electrode fingers of the interdigital transducer electrode; the narrower-pitch electrode finger portion and an electrode finger portion adjacent thereto, of each of the first to third interdigital transducer electrodes, are normally shaped and portions other than the normally-shaped electrode finger portions are apodized; and a ratio of a total of the normally-shaped electrode finger portions adjacent to the narrower-pitch electrode finger portions to a total of the first to third interdigital transducer electrodes except for the narrower-pitch electrode finger portions is about 3% to about 20%.