US 12,395,143 B2
Low pass filter, multilayer-type low pass filter, and method of adjusting filter characteristic
Naoki Mizoguchi, Nagaokakyo (JP)
Assigned to MURATA MANUFACTURING CO., LTD., Kyoto (JP)
Filed by Murata Manufacturing Co., Ltd., Nagaokakyo (JP)
Filed on Mar. 27, 2023, as Appl. No. 18/126,747.
Application 18/126,747 is a continuation of application No. PCT/JP2021/040477, filed on Nov. 3, 2021.
Claims priority of application No. 2020-195572 (JP), filed on Nov. 25, 2020; and application No. 2021-083609 (JP), filed on May 18, 2021.
Prior Publication US 2023/0238934 A1, Jul. 27, 2023
Int. Cl. H03H 7/01 (2006.01); H01F 27/28 (2006.01); H01F 27/40 (2006.01); H01G 4/30 (2006.01); H01G 4/40 (2006.01)
CPC H03H 7/0115 (2013.01) [H01F 27/2804 (2013.01); H01F 27/40 (2013.01); H01G 4/30 (2013.01); H01G 4/40 (2013.01); H01F 2027/2809 (2013.01)] 17 Claims
OG exemplary drawing
 
1. A low pass filter comprising:
a first input/output terminal;
a second input/output terminal;
a signal line connected between the first input/output terminal and the second input/output terminal;
a first inductor connected closest to the first input/output terminal in the signal line;
at least one second inductor connected closer to the second input/output terminal than the first inductor in the signal line; and
a first capacitor connected between ground and a connecting point of the first inductor and the at least one second inductor, or connected between the ground and the connecting point of the first inductor and the at least one second inductor and between the ground and, when the at least one second inductor includes at least two second inductors adjacent to one another, a connecting point of the at least two second inductor; wherein
a second capacitor is connected in parallel to the first inductor, and the first inductor and the second capacitor define a first LC parallel resonator; and
no capacitor is connected in parallel to the at least one second inductor.