| 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 composed of a series arm 17 between input/output terminals 15, 16, and a plurality of parallel arms 19 between the series arm 17 and reference potential terminals 18. The unit element has a first surface acoustic wave resonator 21 inserted in the series arm 17, a second and third surface acoustic wave resonators 22, 23 connected to the parallel arms 19 at the input and output sides, and a first inductance element 24 inserted between a point P1 mutually connected to reference potential terminals of the second and third resonators 22, 23 and a reference potential terminal 18. The second and third resonators 22, 23 have an antiresonant frequency equal to the resonant frequency of the first resonator 21.
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