摘要 |
An acoustic wave filter device having a greatly reduced size includes a balance-unbalance conversion function and an input/output impedance ratio of about 1. The acoustic wave filter device includes a second IDT of a first acoustic wave filter portion that is connected to an unbalanced terminal. The second IDT includes first and second divided IDT portions which are divided in an overlap width direction and connected in series with each other between the unbalanced terminal and a ground potential. A fifth IDT of a second acoustic wave filter portion connected to the first acoustic wave filter portion includes first and second divided IDT portions which are divided in an acoustic wave propagating direction. The first and second divided IDT portions of the fifth IDT are connected to first and second balanced terminals, respectively.
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