Patent ID: 7532090

Claim:
An acoustic wave filter device comprising: a piezoelectric substrate; and a plurality of longitudinally coupled resonator acoustic wave filters provided on the piezoelectric substrate; wherein each of the plurality of longitudinally coupled resonator acoustic wave filters includes an input terminal, an output terminal, an IDT connected to the input terminal, and an IDT connected to the output terminal, the IDT connected to the input terminal and the IDT connected to the output terminal being alternately arranged along an acoustic wave propagating direction; the acoustic wave filter device further comprising: a first terminal connected to the input terminals of the plurality of longitudinally coupled resonator acoustic wave filters; and a second terminal connected to the output terminals of the plurality of longitudinally coupled resonator acoustic wave filters; wherein the plurality of longitudinally coupled resonator acoustic wave filters are withdrawal-weighted, and the withdrawal weighting in at least one of the plurality of longitudinally coupled resonator acoustic wave filters is different from the withdrawal weighting in another of the plurality of longitudinally coupled resonator acoustic wave filters.