Patent ID: 9722574
Date: 2017-08-01
CPC Classifications: H03H

Claim:
1. An acoustic wave device comprising: first and second unbalanced terminals; first and second balanced terminals; a high-frequency filter including a first longitudinally-coupled acoustic wave resonator connected to the first unbalanced terminal, a first one-terminal pair acoustic wave resonator connected in series between the first longitudinally-coupled acoustic wave resonator and the first balanced terminal, and a second one-terminal pair acoustic wave resonator connected in series between the first longitudinally-coupled acoustic wave resonator and the second balanced terminal, the high-frequency filter having a high-frequency passband from a first minimum frequency to a first maximum frequency; and a low-frequency filter including a second longitudinally-coupled acoustic wave resonator connected to the second unbalanced terminal, a third one-terminal pair acoustic wave resonator connected in series between the second longitudinally-coupled acoustic wave resonator and the first balanced terminal, a fourth one-terminal pair acoustic wave resonator connected in series between the second longitudinally-coupled acoustic wave resonator and the second balanced terminal, a fifth one-terminal pair acoustic wave resonator connected in series between the third one-terminal pair acoustic wave resonator and the first balanced terminal, and a sixth one-terminal pair acoustic wave resonator connected in series between the fourth one-terminal pair acoustic wave resonator and the second balanced terminal, the low-frequency filter having a low-frequency passband from a second minimum frequency to a second maximum frequency lower than the first minimum frequency, and at least one of an antiresonant frequency of the third one-terminal pair acoustic wave resonator and an antiresonant frequency of the fourth one-terminal pair acoustic wave resonator being between the second maximum frequency and the first minimum frequency.