JPS57123711A - Optical receiving circuit - Google Patents

Optical receiving circuit

Info

Publication number
JPS57123711A
JPS57123711A JP56009841A JP984181A JPS57123711A JP S57123711 A JPS57123711 A JP S57123711A JP 56009841 A JP56009841 A JP 56009841A JP 984181 A JP984181 A JP 984181A JP S57123711 A JPS57123711 A JP S57123711A
Authority
JP
Japan
Prior art keywords
amplifier
feedback
circuit
fet7
nonlinearity
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
JP56009841A
Other languages
Japanese (ja)
Inventor
Yoshio Ogushi
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.)
NEC Corp
Original Assignee
NEC Corp
Nippon Electric Co 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 NEC Corp, Nippon Electric Co Ltd filed Critical NEC Corp
Priority to JP56009841A priority Critical patent/JPS57123711A/en
Publication of JPS57123711A publication Critical patent/JPS57123711A/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
    • 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

Landscapes

  • Engineering & Computer Science (AREA)
  • Multimedia (AREA)
  • Control Of Amplification And Gain Control (AREA)
  • Optical Communication System (AREA)

Abstract

PURPOSE:To improve the distortion characteristics of an automatic gain control circuit by transducing input light into an electric signal, and controlling the amount of feedback by varying the drain-source equivalent resistance of the FET of a feedback amplifier which inputs said electric signal. CONSTITUTION:An optical signal is transduced into an electric signal, which is inputted to a feedback amplifier 8. A feedback circuit consisting of resistances 10 and 11 in the amplifier 8 nearly determines the gain of the feedback amplifier, and an attenuating circuit consisting of resistances 9 and 12, and an FET13 is cascaded to it; and the amplification degree of the amplifier 8 increases or decreases with the amount of attenuation of the circuit 14. The output of the amplifier 8 is detected by a level detecting circuit 6, whose detection signal controls the gates of an FET7 connected to the input of the amplifier 8, and the FET13. Then nonlinearity of the FET7 and that of the amplifier 8 cancel with each other, and the nonlinearity of the amplifier 8 varies so that the nonlinearity of the FET7 is compensated, so an AGC circuit has wide permissible light-input level range and excellent linearity.
JP56009841A 1981-01-24 1981-01-24 Optical receiving circuit Pending JPS57123711A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP56009841A JPS57123711A (en) 1981-01-24 1981-01-24 Optical receiving circuit

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP56009841A JPS57123711A (en) 1981-01-24 1981-01-24 Optical receiving circuit

Publications (1)

Publication Number Publication Date
JPS57123711A true JPS57123711A (en) 1982-08-02

Family

ID=11731342

Family Applications (1)

Application Number Title Priority Date Filing Date
JP56009841A Pending JPS57123711A (en) 1981-01-24 1981-01-24 Optical receiving circuit

Country Status (1)

Country Link
JP (1) JPS57123711A (en)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS6141213A (en) * 1984-08-01 1986-02-27 Sumitomo Electric Ind Ltd Current/voltage conversion section of optical receiver circuit
JPH0227809A (en) * 1988-07-18 1990-01-30 Fujitsu Ltd Electronic circuit
JPH0496149U (en) * 1990-10-11 1992-08-20

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS6141213A (en) * 1984-08-01 1986-02-27 Sumitomo Electric Ind Ltd Current/voltage conversion section of optical receiver circuit
JPH0227809A (en) * 1988-07-18 1990-01-30 Fujitsu Ltd Electronic circuit
JPH0496149U (en) * 1990-10-11 1992-08-20

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