| 摘要 |
PROBLEM TO BE SOLVED: To increase the attenuation of a surface acoustic wave element in a frequency range outside its pass band without increasing the insertion loss. SOLUTION: The surface acoustic wave element comprises a plurality of unit elements, each comprising a first surface acoustic wave resonator 21 disposed on a series arm 17; a second surface acoustic wave resonator 22 and a third surface acoustic wave resonator 23 connected to a parallel arm 19 at an input terminal side of the first surface acoustic wave resonator 21 and a parallel arm 19 at an output terminal side and including an anti-resonant frequency matching a resonant frequency of the first surface acoustic wave resonator 21; and an inductance element 24 disposed between a connecting point P<SB>1</SB>connecting reference potential terminal sides of the second surface acoustic wave resonator 22 and the third surface acoustic wave resonator 23 and a reference potential terminal 18, wherein the resonant frequencies formed from the capacitance of the first, second and third surface acoustic wave resonators 21, 22, 23 and the first inductance element 24 match each other. COPYRIGHT: (C)2007,JPO&INPIT
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