Patent ID: 11881841
Assignee: MURATA MANUFACTURING CO., LTD.
Field: Basic communication processes (Electrical engineering)
Classification: CPC H | IPC H

Claim 0:
1. A multiplexer comprising:
a plurality of filters; and
a plurality of matching circuits respectively provided to the plurality of filters; wherein
one input/output terminal of each of the plurality of filters is connected to a common terminal;
a first filter included in the plurality of filters is a ladder filter, and includes:
at least one series arm resonator connected on a path connecting the common terminal and another input/output terminal of the first filter;
a plurality of parallel arm resonators connected between a corresponding connection node provided on the path and a ground; and
a first switch which is connected in series with a first parallel arm resonator of the plurality of parallel arm resonators that is connected closest to the common terminal among the plurality of parallel arm resonators, and switches between conduction and non-conduction of the connection node to which the first parallel arm resonator is connected and the ground by a control signal from a controller;

at least one of the plurality of parallel arm resonators is not connected in series with a switch that switches between conduction and non-conduction of the connection node to which the at least one of the parallel arm resonators is connected and the ground by a control signal from the controller;
no switch is connected in parallel with any of the at least one series arm resonator; and
the plurality of matching circuits adjust impedances between the plurality of filters and the common terminal.