Patent ID: 8581674

Claim:
A filter comprising: an acoustic wave device; a wiring board configured to mount the acoustic wave device thereon, comprising an input signal terminal electrically connected to the acoustic wave device via a first signal line; an output signal terminal electrically connected to the acoustic wave device via a second signal line; a first inductor comprising one end connected to the first signal line and the other end connected to ground via a parasitic inductance; and a series resonance circuit comprising an output-side capacitor and a second inductor connected in series with the output-side capacitor, the series resonance circuit comprising one end connected to the second signal line and the other end connected to ground via the parasitic inductance; a first reference potential terminal, wherein the first reference potential terminal is electrically connected to the first inductor and is on a lower surface of the wiring board, the first reference potential terminal separating from a periphery of the wiring board; and a second reference potential terminal, wherein the second reference potential terminal is electrically connected to the second inductor and is on the lower surface of the wiring board, the second reference potential terminal being arranged apart from the first reference potential terminal, the second reference potential terminal separating from the periphery of the wiring board.