Title:
FREQUENCY VARIABLE TYPE LOW-PASS FILTER
Document Type and Number:
Japanese Patent JPS6187409
Kind Code:
A
Abstract:
PURPOSE: To change the cut-off frequency while a referenced frequency characteristic is preserved by controlling a termination capacitor value for input/output and an input admittance of an FDNR circuit in an LPF using the FDNR circuit.
CONSTITUTION: In changing the cut-off frequency from f0 to (fm), values of an input capacitor Cin and an output capacitor Cout are changed respectively in proportion to f0/fm. Further, input admittances D1∼Dn of the FDNR circuits F1∼Fn are changed respectively in proportion to (f0/fm)2. The cut-off frequency is changed while the referenced frequency characteristic is preserved.
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Inventors:
FUNAHARA RIICHI
MIYAGAWA TAKAO
MIYAGAWA TAKAO
Application Number:
JP20897584A
Publication Date:
May 02, 1986
Filing Date:
October 03, 1984
Export Citation:
Assignee:
MURATA MANUFACTURING CO
International Classes:
H03H11/10; H03H7/12; H03H11/04; (IPC1-7): H03H7/01; H03H11/04
Domestic Patent References:
| JPS56104232U | 1981-08-14 | |||
| JPS551080A | 1980-01-07 |
Attorney, Agent or Firm:
Yoshito Yamada