Patent ID: 9742377
Date: 2017-08-22
CPC Classifications: H03H

Claim:
1. A filter comprising: a single substrate; one or more series resonators that are connected in series between an input terminal and an output terminal; one or more parallel resonators that are connected in parallel between the input terminal and the output terminal; and a laterally coupled resonator that is connected in parallel with at least one of the one or more series resonators, wherein: the laterally coupled resonator has a first piezoelectric film portion, a first lower electrode and a plurality of upper electrodes, the first lower electrode and the plurality of upper electrodes sandwiching the first piezoelectric film portion; each of the one or more series resonators and the one or more parallel resonators is a piezoelectric thin film resonator that has a second piezoelectric film portion, a second lower electrode and a second upper electrode, the second lower electrode and the second upper electrode sandwiching the second piezoelectric film portion; a material of the first piezoelectric film portion is the same as a material of the second piezoelectric film portion; a thickness of the first piezoelectric film portion is substantially the same as a thickness of the second piezoelectric film portion; and the one or more series resonators, the one or more parallel resonators and the laterally coupled resonator are formed on the single substrate.