US 11,811,393 B2
Multiplexer, radio frequency front-end circuit, and communication device
Toshiaki Takata, Nagaokakyo (JP)
Assigned to MURATA MANUFACTURING CO., LTD., Kyoto (JP)
Filed by Murata Manufacturing Co., Ltd., Nagaokakyo (JP)
Filed on Nov. 4, 2020, as Appl. No. 17/088,640.
Application 17/088,640 is a continuation of application No. PCT/JP2019/016578, filed on Apr. 18, 2019.
Claims priority of application No. 2018-093245 (JP), filed on May 14, 2018.
Prior Publication US 2021/0050845 A1, Feb. 18, 2021
Int. Cl. H04B 1/00 (2006.01); H03H 9/72 (2006.01); H03F 3/19 (2006.01); H03H 9/02 (2006.01); H03H 9/145 (2006.01); H03H 9/25 (2006.01); H03H 9/64 (2006.01); H04B 1/40 (2015.01)
CPC H03H 9/72 (2013.01) [H03F 3/19 (2013.01); H03H 9/02559 (2013.01); H03H 9/02866 (2013.01); H03H 9/145 (2013.01); H03H 9/25 (2013.01); H03H 9/6496 (2013.01); H04B 1/40 (2013.01); H03F 2200/451 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A multiplexer comprising:
a first filter on a first path connecting a common terminal and a first terminal; and
a second filter on a second path connecting the common terminal and a second terminal, the second filter having a passband that overlaps a generation frequency of a Rayleigh wave ripple in the first filter; wherein
the first filter includes:
a plurality of series arm resonators on the first path; and
a first parallel arm resonator between a connection node provided on the first path and ground, the connection node being provided on a side closer to the first terminal than a first series arm resonator, the first series arm resonator being one of the plurality of series arm resonators connected closest to the common terminal;
the plurality of series arm resonators and the first parallel arm resonator utilize an SH wave as a main mode; and
a number of electrode finger pairs of the first series arm resonator is fewest among numbers of electrode finger pairs of the plurality of series arm resonators.