Acoustic wave device
AssigneeMurata Manufacturing Co., Ltd.
InventorsTakao MUKAI, Daisuke AJIMA, Masaru YATA
Life of this patent
Estimating the term…
Abstract
A longitudinally-coupled resonator-type acoustic wave device includes first to third IDT electrodes disposed on a piezoelectric material and first and second reflectors disposed in acoustic wave propagation directions. Each of any two IDT electrodes adjacent to each other in the acoustic wave propagation directions, of the first to third IDT electrodes, has a narrower-pitch electrode finger portion at an edge thereof adjacent to the other IDT electrode. Most portions of the first to third IDT electrodes are apodized, and the narrower-pitch electrode finger portions and the electrode finger portions adjacent thereto are normally shaped.
Claims6
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%.
Dependencies are inferred from the claim text.