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GB1108070A - Improvements in or relating to receivers with automatic gain control means - Google Patents

Improvements in or relating to receivers with automatic gain control means

Info

Publication number
GB1108070A
GB1108070A GB734367A GB734367A GB1108070A GB 1108070 A GB1108070 A GB 1108070A GB 734367 A GB734367 A GB 734367A GB 734367 A GB734367 A GB 734367A GB 1108070 A GB1108070 A GB 1108070A
Authority
GB
United Kingdom
Prior art keywords
conductive
diode
voltage
transistor
biased
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.)
Expired
Application number
GB734367A
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.)
Telefunken Patentverwertungs GmbH
Original Assignee
Telefunken Patentverwertungs GmbH
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 Telefunken Patentverwertungs GmbH filed Critical Telefunken Patentverwertungs GmbH
Publication of GB1108070A publication Critical patent/GB1108070A/en
Expired 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
    • H03G3/3052—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
    • H03G3/3073—Circuits generating control signals when no carrier is present, or in SSB, CW or pulse receivers
    • 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
    • H03G3/3052—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
    • 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
    • H03G3/3052—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
    • H03G3/3068—Circuits generating control signals for both R.F. and I.F. stages

Landscapes

  • Input Circuits Of Receivers And Coupling Of Receivers And Audio Equipment (AREA)
  • Circuits Of Receivers In General (AREA)
  • Control Of Amplification And Gain Control (AREA)

Abstract

1,108,070. Automatic gain control. TELEFUNKEN PATENTVERWERTUNGS G.m.b.H. 15 Feb., 1967 [18 Feb., 1966], No. 7343/67. Heading H3T. In a receiver provided with automatic gain control, an attenuator is also provided in the signal input channel, together with means dependent upon the input signal level to bring it into operation when the input voltage exceeds a predetermined value, and thereafter to switch it out of circuit if subsequently the input voltage falls below a second predetermined level. Inserted in the lead from aerial 3 to R.F. amplifier 4 is an attenuator in the form of series resistor 19 which can be short-circuited for A.C. by means of diode 20, blocking capacitors 21 together with R.F. chokes provide for feeding a switching voltage to the diode. This switching voltage is derived from the collector circuits of transistors 22, 23, which are cross-coupled to form a bi-stable circuit. At low signal levels transistor 22 is conductive, and transistor 23 non-conductive, so that diode 20 is biased conductive and the attenuation a minimum. The base of transistor 22 is coupled by means of a Zener diode 11 to the A.G.C. generator 10 which produces a positive voltage decreasing as the signal input increases, and at a high signal level, beyond which overloading of the receiver would occur, the potential across Zener diode 11, falls below the contact potential and it becomes conductive. Transistor 22 is then biased non-conductive and transistor 23 becomes conductive, so that diode 20 is biased non-conductive and attenuation occurs. Zener diode 11 is then biased to be non-conductive and it is not until the signal input level falls sufficiently for the A.G.C. voltage to rise enough for the voltage across the Zener diode 11 to exceed the Zener voltage that this diode again becomes conductive. It then applies a positive voltage to the base of transistor 22 which causes the bi-stable circuit to reverse and again make diode 20 conductive, removing the attenuation.
GB734367A 1966-02-18 1967-02-15 Improvements in or relating to receivers with automatic gain control means Expired GB1108070A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
DE1966T0030480 DE1280349B (en) 1966-02-18 1966-02-18 Receiver with automatic regulation to an approximately constant output voltage

Publications (1)

Publication Number Publication Date
GB1108070A true GB1108070A (en) 1968-04-03

Family

ID=7555610

Family Applications (1)

Application Number Title Priority Date Filing Date
GB734367A Expired GB1108070A (en) 1966-02-18 1967-02-15 Improvements in or relating to receivers with automatic gain control means

Country Status (2)

Country Link
DE (1) DE1280349B (en)
GB (1) GB1108070A (en)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0016705A1 (en) * 1979-03-20 1980-10-01 Thomson-Csf R.F. stage with automatic gain control and receiver comprising such a circuit
GB2242088A (en) * 1990-03-14 1991-09-18 Gen Electric Co Plc Radio receiver arrangement with by-pass for rf pre-amplifier
GB2305034A (en) * 1995-08-24 1997-03-26 Nec Corp Attenuation control with lower attenuation below a threshold using a Schmitt trigger
GB2437462B (en) * 2005-03-31 2009-04-22 Intel Corp Transceiver with receive path overload protection and method

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE690807C (en) * 1935-04-16 1940-05-08 Telefunken Gmbh Receiver with automatic shrinkage control
DE1082307B (en) * 1955-10-21 1960-05-25 Texas Instruments Inc Device for automatic control of the gain of a high-frequency amplifier equipped with at least one transistor

Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0016705A1 (en) * 1979-03-20 1980-10-01 Thomson-Csf R.F. stage with automatic gain control and receiver comprising such a circuit
FR2452208A1 (en) * 1979-03-20 1980-10-17 Thomson Csf HEAD HEAD WITH SELF-ADAPTIVE DYNAMIC AND RECEIVER COMPRISING SUCH A HEAD
GB2242088A (en) * 1990-03-14 1991-09-18 Gen Electric Co Plc Radio receiver arrangement with by-pass for rf pre-amplifier
US5230096A (en) * 1990-03-14 1993-07-20 The General Electric Company, P.L.C. Radio receiver antenna arrangements
GB2242088B (en) * 1990-03-14 1994-06-15 Gen Electric Co Plc Radio receiver antenna arrangements
GB2305034A (en) * 1995-08-24 1997-03-26 Nec Corp Attenuation control with lower attenuation below a threshold using a Schmitt trigger
GB2305034B (en) * 1995-08-24 2000-10-25 Nec Corp Apparatus for attenuating a received signal
GB2437462B (en) * 2005-03-31 2009-04-22 Intel Corp Transceiver with receive path overload protection and method

Also Published As

Publication number Publication date
DE1280349B (en) 1968-10-17

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