JPS5652918A - Gain controlling circuit - Google Patents

Gain controlling circuit

Info

Publication number
JPS5652918A
JPS5652918A JP12895179A JP12895179A JPS5652918A JP S5652918 A JPS5652918 A JP S5652918A JP 12895179 A JP12895179 A JP 12895179A JP 12895179 A JP12895179 A JP 12895179A JP S5652918 A JPS5652918 A JP S5652918A
Authority
JP
Japan
Prior art keywords
transistor
input
gain
signal
fet3
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
JP12895179A
Other languages
Japanese (ja)
Inventor
Kazuo Ikeda
Shigeaki Takahashi
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 JP12895179A priority Critical patent/JPS5652918A/en
Publication of JPS5652918A publication Critical patent/JPS5652918A/en
Pending legal-status Critical Current

Links

Classifications

    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03G—CONTROL OF AMPLIFICATION
    • H03G3/00—Gain control in amplifiers or frequency changers without distortion of the input signal
    • H03G3/20—Automatic control
    • H03G3/30—Automatic control in amplifiers having semiconductor devices
    • H03G3/3052—Automatic control in amplifiers having semiconductor devices in bandpass amplifiers (H.F. or I.F.) or in frequency-changers used in a (super)heterodyne receiver

Abstract

PURPOSE:To elevate the performance of a receiver in case of a strong input, by applying an AGC signal to the input terminal of the high frequency amplifier circuit through the switching transistor. CONSTITUTION:An intermediate frequency signal which has been output from the transistor 7 is detected by the diodes 15, 16 through the capacitor 14, and becomes the voltage according to the signal input. The AGC is executed by applying this voltage to the base of the switching transistor 21, and connecting the emitter to the gate of the high frequency amplification FET3. In case of a strong input, the transistor 21 is turned on, the negative potential of the terminal 23 is applied to the gate of FET3, the gain is lowered, and therefore the gain can be adjusted effectively.
JP12895179A 1979-10-08 1979-10-08 Gain controlling circuit Pending JPS5652918A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP12895179A JPS5652918A (en) 1979-10-08 1979-10-08 Gain controlling circuit

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP12895179A JPS5652918A (en) 1979-10-08 1979-10-08 Gain controlling circuit

Publications (1)

Publication Number Publication Date
JPS5652918A true JPS5652918A (en) 1981-05-12

Family

ID=14997436

Family Applications (1)

Application Number Title Priority Date Filing Date
JP12895179A Pending JPS5652918A (en) 1979-10-08 1979-10-08 Gain controlling circuit

Country Status (1)

Country Link
JP (1) JPS5652918A (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6146856A (en) * 1997-05-22 2000-11-14 Xyrofin Oy Process for the production of isomatulose and other products

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS51147236A (en) * 1975-06-13 1976-12-17 Hitachi Ltd Automatic gain control circuit
JPS532506U (en) * 1976-06-25 1978-01-11

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS51147236A (en) * 1975-06-13 1976-12-17 Hitachi Ltd Automatic gain control circuit
JPS532506U (en) * 1976-06-25 1978-01-11

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6146856A (en) * 1997-05-22 2000-11-14 Xyrofin Oy Process for the production of isomatulose and other products

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