| 摘要 |
A surface acoustic wave filter includes series-arm resonators and parallel-arm resonators that are connected in a ladder-like fashion. This surface acoustic wave filter satisfies conditions expressed as: <?in-line-formulae description="In-line Formulae" end="lead"?>1x10<SUP>6</SUP><=4pi<SUP>2</SUP>f<SUB>0</SUB><SUP>2</SUP>R<SUP>2</SUP>CopCos<=3.1x10<SUP>6</SUP><?in-line-formulae description="In-line Formulae" end="tail"?> where Cop is the electrostatic capacitance of the parallel-arm resonators, Cos is the electrostatic capacitance of the series-arm resonators, f<SUB>0 </SUB>is the center frequency, and R is the nominal impedance.
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