| US 7,579,928 B2 | ||
| Surface acoustic wave device and communication device | ||
| Kazuhiro Otsuka, Kyoto (Japan); Tsuyoshi Nakai, Kyoto (Japan); and Hiroyuki Tanaka, Kyoto (Japan) | ||
| Assigned to Kyocera Corporation, Kyoto (Japan) | ||
| Filed on Mar. 30, 2007, as Appl. No. 11/729,953. | ||
| Claims priority of application No. 2006-102499 (JP), filed on Apr. 03, 2006; and application No. 2006-102500 (JP), filed on Apr. 03, 2006. | ||
| Prior Publication US 2007/0290770 A1, Dec. 20, 2007 | ||
| Int. Cl. H03H 9/72 (2006.01); H03H 9/64 (2006.01) | ||
| U.S. Cl. 333—133 [333/193; 333/195; 310/313 B] | 18 Claims |
| 1. A surface acoustic wave device comprising:
a front stage surface acoustic wave resonator comprising an IDT electrode;
a first rear stage surface acoustic wave element and a second rear stage surface acoustic wave element connected in parallel
through the first stage surface acoustic wave resonator, each of the first and second rear stage surface acoustic wave elements
comprising three or more than three odd-number of IDT electrodes;
a signal wiring connecting between the IDT electrode of the front stage surface acoustic wave resonator and the IDT electrode
of one of the first and second rear stage surface acoustic wave elements;
a reference potential wiring connecting between the IDT electrode of the one of the first and second rear stage surface acoustic
wave elements and a reference electric potential electrode;
a capacitor comprising a portion of the signal wiring, a portion of the reference potential wiring facing the portion of the
signal wiring and an insulator interposed between the portion of the signal wiring and the portion of the reference potential
wiring;
an unbalance input/output terminal connected with the IDT electrode of the front stage surface acoustic wave resonator; and
two balanced output/input terminals each connected with the IDT electrode of each of the rear stage surface acoustic wave
elements, respectively,
wherein a width of the portion of the reference potential wiring is different from a width of the portion of the signal wiring.
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