US 12,451,853 B2
Filter device and radio-frequency front-end circuit
Kazuyuki Muramoto, Nagaokakyo (JP); Takuya Sato, Nagaokakyo (JP); and Keisuke Ogawa, Nagaokakyo (JP)
Assigned to MURATA MANUFACTURING CO., LTD., Kyoto (JP)
Filed by Murata Manufacturing Co., Ltd., Nagaokakyo (JP)
Filed on Jan. 5, 2024, as Appl. No. 18/404,945.
Claims priority of application No. 2023-007400 (JP), filed on Jan. 20, 2023.
Prior Publication US 2024/0250654 A1, Jul. 25, 2024
Int. Cl. H03H 1/00 (2006.01); H03H 7/01 (2006.01)
CPC H03H 1/00 (2013.01) [H03H 7/0115 (2013.01); H03H 2001/0085 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A filter device comprising:
a stacked body including a plurality of dielectric layers that are stacked and a first surface and a second surface;
an input terminal, an output terminal, and a ground terminal on the second surface of the stacked body;
a ground electrode inside the stacked body and connected to the ground terminal;
a first resonator and a second resonator provided in a signal transmission path between the input terminal and the output terminal on a dielectric layer of the plurality of between the first surface and the ground electrode; and
a coupling electrode to couple the first resonator and the second resonator by capacitive coupling; wherein
the first resonator includes a first capacitor electrode defining a capacitor with the ground electrode, and the second resonator includes a second capacitor electrode defining a capacitor with the ground electrode;
the coupling electrode is connected to the second capacitor electrode and defines a capacitor with the first capacitor electrode;
the coupling electrode includes a first electrode and a second electrode, each including a first end and a second end;
the first end of the first electrode and the first end of the second electrode are connected to each other; and
the second end of the first electrode and the second end of the second electrode are connected to the second capacitor electrode.