Patent ID: 7479848

Claim:
An acoustic wave filter device having a first attenuation band, a pass band having a first center frequency, the pass band located on a frequency side that is lower than the first attenuation band, and a second attenuation band located on a frequency side that is higher than the first attenuation band, the acoustic wave filter device comprising: first filter circuit portions having first inductors provided in a series arm that couples an input terminal and an output terminal and first acoustic wave resonators serially connected to the first inductors; and a second filter circuit portion having at least one second inductor provided in the series arm, a second acoustic wave resonator connected between one end of the second inductor and a ground potential, and a third acoustic wave resonator connected between the other end of the second inductor and the ground potential; wherein the first filter circuit portions and the second filter circuit portion are serially connected in the series arm; and when the center frequency of a frequency characteristic of an LC filter defined by capacitance components of the first, second and third acoustic wave resonators and inductance components of the first and second inductors is a second center frequency, the second center frequency is higher than the first center frequency.