JPS57155816A - Automatic gain control circuit - Google Patents

Automatic gain control circuit

Info

Publication number
JPS57155816A
JPS57155816A JP4080281A JP4080281A JPS57155816A JP S57155816 A JPS57155816 A JP S57155816A JP 4080281 A JP4080281 A JP 4080281A JP 4080281 A JP4080281 A JP 4080281A JP S57155816 A JPS57155816 A JP S57155816A
Authority
JP
Japan
Prior art keywords
diode
gain
power supply
increased
gain control
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
JP4080281A
Other languages
Japanese (ja)
Inventor
Atsushi Sakamoto
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.)
Fujitsu Ltd
Original Assignee
Fujitsu 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 Fujitsu Ltd filed Critical Fujitsu Ltd
Priority to JP4080281A priority Critical patent/JPS57155816A/en
Publication of JPS57155816A publication Critical patent/JPS57155816A/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
    • H03G3/3005—Automatic control in amplifiers having semiconductor devices in amplifiers suitable for low-frequencies, e.g. audio amplifiers
    • H03G3/301—Automatic control in amplifiers having semiconductor devices in amplifiers suitable for low-frequencies, e.g. audio amplifiers the gain being continuously variable
    • H03G3/3015—Automatic control in amplifiers having semiconductor devices in amplifiers suitable for low-frequencies, e.g. audio amplifiers the gain being continuously variable using diodes or transistors

Abstract

PURPOSE:To smooth the operation of an AGC circuit without being affected by a power supply, by using two PIN diodes having a variable linear resistance. CONSTITUTION:Both ends of a diode D1 are connected to gain control terminals T1 and T2 of an amplifier 1 via DC block capacitors C1 and C2 and the diode acts like a variable resistor adjusting the gain of the amplifier 1. The 2nd PIN diode D2 is inserted between the anode of the PIN diode D1 and a positive power supply +V with the same polarity. With this constitution, as the resistance value of the diode D1 increases with smaller AGC current, the resistance of the diode D2 is increased, allowing to reduce the gain sufficiently through the removal of effect of the power supply. Since the voltage drop of the D1 and D2 is small, the current value is increased so that the gain is sufficiently increased.
JP4080281A 1981-03-20 1981-03-20 Automatic gain control circuit Pending JPS57155816A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP4080281A JPS57155816A (en) 1981-03-20 1981-03-20 Automatic gain control circuit

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP4080281A JPS57155816A (en) 1981-03-20 1981-03-20 Automatic gain control circuit

Publications (1)

Publication Number Publication Date
JPS57155816A true JPS57155816A (en) 1982-09-27

Family

ID=12590757

Family Applications (1)

Application Number Title Priority Date Filing Date
JP4080281A Pending JPS57155816A (en) 1981-03-20 1981-03-20 Automatic gain control circuit

Country Status (1)

Country Link
JP (1) JPS57155816A (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5535444A (en) * 1994-11-04 1996-07-09 Grandfield; Walter Diode loaded feed-forward radio frequency amplifier power control

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5535444A (en) * 1994-11-04 1996-07-09 Grandfield; Walter Diode loaded feed-forward radio frequency amplifier power control

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