| CPC H03H 9/568 (2013.01) [H03H 9/13 (2013.01); H03H 9/70 (2013.01)] | 20 Claims |
|
1. A filter comprising:
a first filter circuit operable in a first frequency band as a pass band; and
an additional circuit connected in parallel to at least a portion of the first filter circuit; wherein
the first filter circuit includes a resonator electrode on a substrate and a main wire connected to the resonator electrode;
the main wire includes a first metal film on the substrate and a second metal film on the first metal film and in contact with the first metal film;
the additional circuit includes an IDT electrode group including a plurality of IDT electrodes on the substrate and a sub-wire on the substrate and connecting the IDT electrode group to the first filter circuit;
at least a portion of the sub-wire includes a third metal film connected to the IDT electrode group;
the third metal film is covered with a fourth metal film with an insulating layer interposed therebetween, the insulating layer being provided on the third metal film; and
the fourth metal film is connected to a ground terminal on the substrate.
|