JPS564922A - Tuning circuit - Google Patents

Tuning circuit

Info

Publication number
JPS564922A
JPS564922A JP7918479A JP7918479A JPS564922A JP S564922 A JPS564922 A JP S564922A JP 7918479 A JP7918479 A JP 7918479A JP 7918479 A JP7918479 A JP 7918479A JP S564922 A JPS564922 A JP S564922A
Authority
JP
Japan
Prior art keywords
voltage
junction
capacity
frequency
frequency voltage
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
JP7918479A
Other languages
Japanese (ja)
Inventor
Michihiro Tateishi
Akinori Maeda
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Hitachi Ltd
Original Assignee
Hitachi Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Hitachi Ltd filed Critical Hitachi Ltd
Priority to JP7918479A priority Critical patent/JPS564922A/en
Publication of JPS564922A publication Critical patent/JPS564922A/en
Pending legal-status Critical Current

Links

Classifications

    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03J—TUNING RESONANT CIRCUITS; SELECTING RESONANT CIRCUITS
    • H03J3/00—Continuous tuning
    • H03J3/02—Details
    • H03J3/16—Tuning without displacement of reactive element, e.g. by varying permeability
    • H03J3/18—Tuning without displacement of reactive element, e.g. by varying permeability by discharge tube or semiconductor device simulating variable reactance
    • H03J3/185—Tuning without displacement of reactive element, e.g. by varying permeability by discharge tube or semiconductor device simulating variable reactance with varactors, i.e. voltage variable reactive diodes

Landscapes

  • Input Circuits Of Receivers And Coupling Of Receivers And Audio Equipment (AREA)

Abstract

PURPOSE:To prevent the capacity of a junction part from varying owing to a high- frequency voltage by using two varactor diodes and then by combining them so that the variation of the junction-part capacity due to the high-frequency voltage will operate in the opposite direction. CONSTITUTION:Through coupling capacitor C2, tuning circuit part 1 is connected to the connection point between series-connected varactor diodes D7 and D8 and a bias voltage is applied by way of resistances 9 and 10 provided in parallel to D7 and D8. The anode side of D7, grounded via high-frequency current path C11, is applied with a fixed bias or control voltage from terminal 13. The cathode side of D8, grounded via high-frequency current path C12, is supplied with a fixed bias or control voltage from terminal 14. A high frequency voltage from circuit 1 operates on both D7 and D8 differing in direction to the variation of capacity due to the high-frequency voltage, and even a strong input never varies the junction-part capacity, so that the deterioration of sensitivity, selectivity, etc., due to detuning can be prevented.
JP7918479A 1979-06-25 1979-06-25 Tuning circuit Pending JPS564922A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP7918479A JPS564922A (en) 1979-06-25 1979-06-25 Tuning circuit

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP7918479A JPS564922A (en) 1979-06-25 1979-06-25 Tuning circuit

Publications (1)

Publication Number Publication Date
JPS564922A true JPS564922A (en) 1981-01-19

Family

ID=13682884

Family Applications (1)

Application Number Title Priority Date Filing Date
JP7918479A Pending JPS564922A (en) 1979-06-25 1979-06-25 Tuning circuit

Country Status (1)

Country Link
JP (1) JPS564922A (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPWO2007135821A1 (en) * 2006-05-19 2009-10-01 株式会社村田製作所 Matching device and antenna matching circuit

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPWO2007135821A1 (en) * 2006-05-19 2009-10-01 株式会社村田製作所 Matching device and antenna matching circuit

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