US 12,438,512 B2
Filter device, and radio-frequency front end circuit provided with same
Masayuki Kikuda, Nagaokakyo (JP)
Assigned to MURATA MANUFACTURING CO., LTD., Kyoto (JP)
Filed by Murata Manufacturing Co., Ltd., Nagaokakyo (JP)
Filed on Oct. 3, 2023, as Appl. No. 18/376,006.
Application 18/376,006 is a continuation of application No. PCT/JP2022/005889, filed on Feb. 15, 2022.
Claims priority of application No. 2021-064115 (JP), filed on Apr. 5, 2021.
Prior Publication US 2024/0030884 A1, Jan. 25, 2024
Int. Cl. H03H 7/01 (2006.01); H03H 7/09 (2006.01)
CPC H03H 7/0161 (2013.01) [H03H 7/0115 (2013.01); H03H 7/09 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A filter device comprising:
a main body;
an input terminal, an output terminal, and a ground terminal in the main body;
a first ground electrode and a second ground electrode at different positions in a normal direction of the main body and connected to the ground terminal; and
a plurality of resonators between the first ground electrode and the second ground electrode in the normal direction and electromagnetically coupled to each other; wherein
each of the plurality of resonators includes:
a first capacitor electrode that at least partially overlaps the first ground electrode when the main body is viewed in plan view from the normal direction;
a second capacitor electrode that at least partially overlaps the second ground electrode when the main body is viewed in plan view from the normal direction; and
a first via that connects the first capacitor electrode and the second capacitor electrode; and
the plurality of resonators include:
a first resonator connected to the input terminal;
a second resonator connected to the output terminal; and
a third resonator and a fourth resonator in a region between the first resonator and the second resonator;
the filter device further comprising a second via in a region between the third resonator and the fourth resonator when the main body is viewed in plan view from the normal direction and connected to the first ground electrode and the second ground electrode.