US 12,323,122 B2
Filter circuit and multilayered filter device
Masahiro Tatematsu, Tokyo (JP); Shuhei Sawaguchi, Tokyo (JP); Yuta Ashida, Tokyo (JP); Tetsuzo Goto, Tokyo (JP); Yoshinori Matsumaru, Tokyo (JP); Shigemitsu Tomaki, Tokyo (JP); and Longfei Yi, Tokyo (JP)
Assigned to TDK CORPORATION, Tokyo (JP)
Filed by TDK CORPORATION, Tokyo (JP)
Filed on Jan. 31, 2023, as Appl. No. 18/162,155.
Claims priority of application No. 2022-016356 (JP), filed on Feb. 4, 2022.
Prior Publication US 2023/0253945 A1, Aug. 10, 2023
Int. Cl. H03H 7/01 (2006.01); H01F 27/28 (2006.01); H01F 27/29 (2006.01); H01G 4/012 (2006.01); H01G 4/30 (2006.01)
CPC H03H 7/0115 (2013.01) [H01F 27/2804 (2013.01); H01F 27/292 (2013.01); H01G 4/012 (2013.01); H01G 4/30 (2013.01); H03H 7/0161 (2013.01); H01F 2027/2809 (2013.01)] 22 Claims
OG exemplary drawing
 
1. A filter circuit comprising:
a pair of balanced input ports;
a pair of balanced output ports;
a first resonator and a second resonator provided in parallel between the pair of balanced input ports and the pair of balanced output ports in a circuit configuration;
a first capacitor connected in parallel to the first resonator; and
a second capacitor connected in parallel to the second resonator, wherein
the first resonator and the second resonator are magnetically coupled to each other and electrically connected to each other,
the first capacitor and the second capacitor are not electrically connected to ground,
the first resonator includes a first inductor wound around a first axis, and
the second resonator includes a second inductor wound around a second axis.