Title:
可変バンドパスフィルタ
Document Type and Number:
Japanese Patent JP6886425
Kind Code:
B2
Abstract:
To provide a variable band-pass filter including a double tuner having multiple LC series resonators in which the range of mean frequency is widened.SOLUTION: A variable band-pass filter 3 includes multiple series resonators 31 including a resonance inductor Lhaving a fixed inductance and a resonance capacitor Chaving a variable capacitance in series, respectively, and a coupling circuit 32 for coupling the series resonators 31 each other. The coupling circuit 32 is configured by parallel synthesis of an inductive gyrator coupling circuit including a shunt inductor-M having a negative inductance, and a capacitive gyrator coupling circuit including a shunt capacitor +Chaving a positive capacitance in a two terminal pair circuit. Two resonance inductors of the coupling circuit are wound around a common toroidal core having a low magnetic permeability, so that tradeoff between attenuation characteristics and insertion loss is optimized.SELECTED DRAWING: Figure 5
Inventors:
Takashi Chiba
Yokono Satoshi
Kazuo Yamashita
Yokono Satoshi
Kazuo Yamashita
Application Number:
JP2018067586A
Publication Date:
June 16, 2021
Filing Date:
March 30, 2018
Export Citation:
Assignee:
Japan Radio Co., Ltd.
International Classes:
H03H7/12; H03H7/075; H03J3/20
Domestic Patent References:
| JP201377663A | ||||
| JP2001313580A | ||||
| JP2000341071A | ||||
| JP6350374A | ||||
| JP5023782B1 | ||||
| JP2017147542A |
Attorney, Agent or Firm:
Kenji Okada
Masaaki Hata
Mari Tanaka
Katsuhiro Imashita
Masaaki Hata
Mari Tanaka
Katsuhiro Imashita