Patent ID: 11901879
Assignee: MURATA MANUFACTURING CO., LTD.
Field: Basic communication processes (Electrical engineering)
Classification: CPC H | IPC H

Claim 0:
1. A multiplexer comprising:
a common terminal, a first input/output terminal, and a second input/output terminal;
a plurality of filters connected to the common terminal, wherein:
a first filter is arranged between the common terminal and the first input/output terminal, the first filter having a first pass band; and
a second filter is arranged between the common terminal and the second input/output terminal, the second filter including at least one acoustic wave resonator, and having a second pass band located at a higher frequency than the first pass band;

a first capacitor that is serially arranged on a connection path between the common terminal and the first filter; and
a second capacitor that is serially arranged on a connection path between the common terminal and the second filter,
wherein the at least one acoustic wave resonator of the second filter utilizes leaky waves that propagate along a piezoelectric substrate composed of LiTaO3 as surface acoustic waves or at least one acoustic wave resonator having a stacked structure comprising a high-acoustic-velocity support substrate, a low-acoustic-velocity film, and a piezoelectric layer,
wherein when the second filter is regarded as a capacitance, a Q value of the second capacitor in the first pass band is higher than a Q value of the capacitance in the first pass band, and
wherein a capacitance value of the second capacitor is lower than or equal to 3 pF.