US2483314A - Superheterodyne receiver comprising automatic frequency control - Google Patents

Superheterodyne receiver comprising automatic frequency control Download PDF

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Publication number
US2483314A
US2483314A US661522A US66152246A US2483314A US 2483314 A US2483314 A US 2483314A US 661522 A US661522 A US 661522A US 66152246 A US66152246 A US 66152246A US 2483314 A US2483314 A US 2483314A
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US
United States
Prior art keywords
frequency
circuit
carrier
filter
amplifier
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 - Lifetime
Application number
US661522A
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English (en)
Inventor
Groot Folkert Albert De
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.)
Hartford National Bank and Trust Co
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Hartford National Bank and Trust Co
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Filing date
Publication date
Application filed by Hartford National Bank and Trust Co filed Critical Hartford National Bank and Trust Co
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Publication of US2483314A publication Critical patent/US2483314A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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Classifications

    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03J—TUNING RESONANT CIRCUITS; SELECTING RESONANT CIRCUITS
    • H03J7/00—Automatic frequency control; Automatic scanning over a band of frequencies
    • H03J7/02—Automatic frequency control
    • H03J7/04—Automatic frequency control where the frequency control is accomplished by varying the electrical characteristics of a non-mechanically adjustable element or where the nature of the frequency controlling element is not significant
    • H03J7/042—Automatic frequency control where the frequency control is accomplished by varying the electrical characteristics of a non-mechanically adjustable element or where the nature of the frequency controlling element is not significant with reactance tube
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03J—TUNING RESONANT CIRCUITS; SELECTING RESONANT CIRCUITS
    • H03J7/00—Automatic frequency control; Automatic scanning over a band of frequencies
    • H03J7/02—Automatic frequency control
    • H03J7/04—Automatic frequency control where the frequency control is accomplished by varying the electrical characteristics of a non-mechanically adjustable element or where the nature of the frequency controlling element is not significant
    • H03J7/14—Controlling the magnetic state of inductor cores
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B1/00—Details of transmission systems, not covered by a single one of groups H04B3/00 - H04B13/00; Details of transmission systems not characterised by the medium used for transmission
    • H04B1/06—Receivers
    • H04B1/16—Circuits
    • H04B1/30—Circuits for homodyne or synchrodyne receivers
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B1/00—Details of transmission systems, not covered by a single one of groups H04B3/00 - H04B13/00; Details of transmission systems not characterised by the medium used for transmission
    • H04B1/06—Receivers
    • H04B1/16—Circuits
    • H04B1/30—Circuits for homodyne or synchrodyne receivers
    • H04B1/302—Circuits for homodyne or synchrodyne receivers for single sideband receivers

Definitions

  • the invention relates tol improvements in. or
  • the said: specification relates to. a. super heterodyne receiver whose intermediate frequencypartcomprisesa sharpfilter for the:selec- 51011201 the carrier wave; in; which .a control voltagefonautomatic frequency-control is generated with. the aid ofa frequency discriminator of.
  • The; filter may comprise one:v
  • a filter comprising. one or: more.
  • The; objectcf the present invention is. to.-provid'e; an, especially suitable form of. construction of; the receiver above described which: ensuresanrin proved .1 performance.
  • the-said frequency discriminatorisccnstructedvin such manner. that'- the ;automatic;frequency-control occurs: solely or substantially. solely as; a. function of" the detuning Ofr the filter' with respect toi the carrier wave;
  • The: said; frequency discriminator is; usually". constructed. in; such-v manner that:- the carrien 55 661,523 ,1 filed April.
  • phase andin antiphasezytm a couple, of :pushpull connected COHtIYOIEI'GCtifiEIS and which, if.-
  • the tuning of thefilteris correct, have. a given phase displacement which will be referred tohereinafter as: the normal phase. displacementand which is'usuallyz909.
  • the discriminator network in additionatothe filter whose tuning'is controlled comprises-zone; orrmore uncontrolled resonant circuits", the-phase displacement,
  • intermediate frequency circuits of. the. network have suchaqua'lity for the frequency of the intermediate frequency; carrier wave that they do not cause .a relativephase. displacement between. the voltages applied to the controlnrectifiersing phase and in antiphase-respectively; Ifthis cone dition is satisfied, thesecircuits nolonger infiuence the value. of the control voltage-so thatv the automatic frequency-control merely depends upon the'detuning of the filter-with::respect-to the carrier wave.
  • the single-figureof the drawing represents the, intermediate frequency portion: of a: receiver towhich the invention is applied.
  • Anintermediate frequency amplifying tube 1- is coupled; to" the control grid circuit of a discharge tube. l via a: resonant circuit. 2 tuned ,torthezzintermediate ire-- quencyand a filter 3 formed by; a resonant; cir-- cuit with regenerative-feedback.
  • The: filter" 3 is
  • the anode circuit of the discharge tube t includes a circuit 9 tuned to the intermediate-frequency and coupled capacitatively via a condenser lll to a diode-detector 1 whose audio-frequency output voltage is supplied to an audiofrequency amplifier (not shown).
  • the circuit 2 has connected to it a circuit l2 which is also tuned to the intermediate-frequency and which has connected to it two push-pull connected control rectifiers (diodes) l3 and M.
  • the centre of the circuit l2 and the centre of the output resistance it of the two diodes l3 and M are connected to a coupling coil [6 which is coupled inductively to the intermediate-frequency circuit 9.
  • the circuits 1, 9 and i2 and the coupling coil H5 constitute a discriminator network which jointly with the control rectifiers l3 and 14 connected to it constitutes a device for generating a control voltage for automatic frequency-control, said control voltage being set up across the said output resistance l5.
  • the control voltage is supplied to the control-grid of a discharge tube ll shown in the drawing as a triode, whose anode current is passed through a magnetising coil 8.
  • the inductance 6 is provided with a core of high-frequency iron on which the magnetising coil I8 is fitted. Variation of the direct current passing through this coil permits of varying the inductance of the coil 6 and hence the tuning of the sharp circuit 3 within certain limits.
  • the sideband frequencies of the intermediate-frequency signal are strongly attenuated with respect to the carrier wave, so that the risk of an apparent over-modulation of the signal occurring in the event of selective fading, which would be accompanied by a Strong non-linear distortion of the low-frequency signal, is avoided.
  • the linear distortion brought about by the attenuation of the sideband frequencies is elminated by a suitable choice of the frequency characteristic curve of the audio-frequency amplifier.
  • the desired operation requires that the tuning frequency of the circuit 3 always corresponds within narrow limits with the frequency of the intermediate-frequency carrier wave.
  • This conformity is ensured by the automatic frequency-control, since, in the event of a divergence occurring between the said frequencies a control 6 voltage of proper polarity is generated across the resistance and modifies the inductance of the coil 6, to such an extent that the tuning frequency of the circuit 3 is again substantially put into agreement with the carrier wave frequency.
  • the frequency-control should depend solely or substantially solely upon the detuning of the circuit 3 with respect to the carrier wave and should not depend at the same time upon the frequency difference between the carrier wave and the tuning of the uncontrolled intermediate-frequency circuits 9 and I2.
  • the circuits 9 and [2 are constructed in such manner 7 that their quality factor is identical or substantially identical for the frequency of the intermediate-frequency carrier wave.
  • the two circuits are of equal quality, they cause no relative phase displacement between the voltages supplied to the control rectifiers in phase and in antiphase respectively and consequently the output resistance I5 has occurring across it a control voltage which depends solely upon the phase displacement caused by the detuning of the circuit 3 with respect to the carrier wave, since the phase displacements occurring by reason of the frequency difference between the carrier wave and the tuning of the circuits 9 and 12, are identical and hence do not contribute towards a relative phase displacement between the said voltages.
  • An amplifier circuit arrangement particularly for use in a receiver for receiving signal voltages of carrier and sideband frequencies, comprising an amplifier having an input circuit and an output circuit for translating a first signal voltage having frequency components corresponding to said carrier and said sideband frequencies, a filter circuit sharply tuned to a frequency corresponding to said carrier frequency and coupled to the input circuit of said amplifier to apply a signal voltage of frequency corresponding to said carrier and sideband frequencies to said amplifier, means to couple said filter circuit to said amplifier to derive and apply to the input circuit of said amplifier a second signal voltage of frequency corresponding to said carrier frequency to reduce the damping of said filter, a frequency discriminator circuit having a first resonant circuit coupled to the input circuit and a second resonant circuit coupled to the output circuit of said amplifier to produce a frequency control voltage, means responsive to said control voltage to tune said filter sharply to an intermediate frequency corresponding to said carrier frequency, said first and said second resonant circuits having quality factors such that said frequency control voltage varies substantially solely proportional to the difference in frequency between the frequency to which said filter
  • An amplifier circuit arrangement particularly for use in a receiver for receiving signal voltages of carrier and sideband frequencies, comprising an amplifier having an input circuit and an output circuit for translating a first signal voltage having frequency components corresponding to said carrier and said sideband frequencies, a filter circuit sharply tuned to a frequency corresponding to said carrier frequency and coupled to the input circuit of said amplifier to apply a signal voltage of frequency corresponding to said carrier and sideband frequencies to said amplifier, means to couple said filter circuit to said amplifier to derive and apply to the input circuit of said amplifier a second signal voltage of frequency corresponding to said carrier frequency to reduce the damping of said filter, a frequency discriminator circuit having a first resonant circuit coupled to the input circuit and a second resonant circuit coupled to the output circuit of said amplifier to produce a frequency control voltage, means responsive to said control voltage to tune said filter sharply to an intermediate frequency corresponding to said carrier frequency, said first and said second resonant circuits having substantially equal quality factors whereby said frequency control voltage varies substantially solely proportional to the difference in frequency between the frequency to which
  • An amplifier circuit arrangement particularly for use in a receiver for receiving signal voltages of carrier and sideband frequencies, comprising an amplifier having an input circuit and an output circuit for translating a first signal voltage having frequency components corresponding to said carrier and said sideband frequencies, a filter circuit sharply tuned to a frequency corresponding to said carrier frequency and coupled to the input circuit of said amplifier to apply a signal voltage of frequency corresponding to said carrier and sideband frequencies to said amplifier, means to couple said filter circuit to said amplifier to derive and apply to the input circuit of said amplifier a second signal voltage of frequency corresponding said carrier frequency to reduce the damping of said filter, a frequency discriminator circuit having a first resonant circuit coupled to the input circuit and a second resonant circuit coupled to the output circuit of said amplifier to produce a frequency control voltage, means responsive to said control voltage to tune said filter sharply to an intermediate frequency corresponding to said carrier frequency, said first, said second resonant circuits having quality factors producing substantially equal phase displacements of the voltages there across whereby said frequency control voltage varies only in proportion to the frequency

Landscapes

  • Engineering & Computer Science (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Signal Processing (AREA)
  • Power Engineering (AREA)
  • Superheterodyne Receivers (AREA)
  • Stabilization Of Oscillater, Synchronisation, Frequency Synthesizers (AREA)
  • Amplifiers (AREA)
  • Noise Elimination (AREA)
  • Networks Using Active Elements (AREA)
US661522A 1941-08-16 1946-04-12 Superheterodyne receiver comprising automatic frequency control Expired - Lifetime US2483314A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
NL102584A NL65489C (fr) 1941-08-16 1941-08-16

Publications (1)

Publication Number Publication Date
US2483314A true US2483314A (en) 1949-09-27

Family

ID=40627386

Family Applications (3)

Application Number Title Priority Date Filing Date
US661521A Expired - Lifetime US2483889A (en) 1941-08-16 1946-04-12 Superheterodyne receiver with automatic frequency control
US661522A Expired - Lifetime US2483314A (en) 1941-08-16 1946-04-12 Superheterodyne receiver comprising automatic frequency control
US662963A Expired - Lifetime US2595931A (en) 1941-08-16 1946-04-18 Superheterodyne receiver with automatic frequency control

Family Applications Before (1)

Application Number Title Priority Date Filing Date
US661521A Expired - Lifetime US2483889A (en) 1941-08-16 1946-04-12 Superheterodyne receiver with automatic frequency control

Family Applications After (1)

Application Number Title Priority Date Filing Date
US662963A Expired - Lifetime US2595931A (en) 1941-08-16 1946-04-18 Superheterodyne receiver with automatic frequency control

Country Status (7)

Country Link
US (3) US2483889A (fr)
BE (1) BE446845A (fr)
CH (2) CH231618A (fr)
DE (3) DE869223C (fr)
FR (3) FR885191A (fr)
GB (3) GB616358A (fr)
NL (2) NL65489C (fr)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2891158A (en) * 1951-06-30 1959-06-16 Cgs Lab Inc Ferrite stabilizing system

Families Citing this family (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2857479A (en) * 1953-03-20 1958-10-21 Bell Telephone Labor Inc Distortion reducing tuned amplifier
US2811639A (en) * 1953-05-26 1957-10-29 Cgs Lab Inc Signal generating apparatus
US2882391A (en) * 1954-09-07 1959-04-14 Gen Motors Corp Electric radio tuner
DE1158128B (de) * 1959-04-27 1963-11-28 Robertshaw Fulton Controls Co Empfaenger fuer phasenmodulierte Hochfrequenzschwingungen
US3676582A (en) * 1971-03-03 1972-07-11 Gen Electric Emphasized carrier circuit with integral afc operation
US5552036A (en) * 1994-06-01 1996-09-03 Foret; Todd L. Process for reducing the level of sulfur in a refinery process stream and/or crude oil
JP5348322B2 (ja) * 2010-05-28 2013-11-20 株式会社村田製作所 電力伝送システム
TWI608694B (zh) * 2015-05-13 2017-12-11 Fu Tzu Hsu Static magnetoresistive magnetic amplifying device

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1642173A (en) * 1921-03-16 1927-09-13 Rca Corp Radio signaling system
US1681532A (en) * 1923-07-02 1928-08-21 Western Electric Co Transmission control
US2121103A (en) * 1935-10-17 1938-06-21 Rca Corp Frequency variation response circuits
US2302893A (en) * 1939-09-29 1942-11-24 Rca Corp Variable inductance arrangement

Family Cites Families (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB407057A (en) * 1932-09-09 1934-03-09 James Robinson Improvements in or relating to selective receivers for wave signals
US2133849A (en) * 1934-06-07 1938-10-18 Gen Electric Means for tuning receiving systems
GB469077A (en) * 1936-01-10 1937-07-12 James Robinson Improvements in or relating to wireless and like receivers
US2200038A (en) * 1938-03-19 1940-05-07 Rca Corp Automatic frequency control circuit
US2268672A (en) * 1938-05-24 1942-01-06 Radio Patents Corp Selective amplifier
BE442115A (fr) * 1940-02-29

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1642173A (en) * 1921-03-16 1927-09-13 Rca Corp Radio signaling system
US1681532A (en) * 1923-07-02 1928-08-21 Western Electric Co Transmission control
US2121103A (en) * 1935-10-17 1938-06-21 Rca Corp Frequency variation response circuits
US2302893A (en) * 1939-09-29 1942-11-24 Rca Corp Variable inductance arrangement

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2891158A (en) * 1951-06-30 1959-06-16 Cgs Lab Inc Ferrite stabilizing system

Also Published As

Publication number Publication date
DE889313C (de) 1953-09-10
NL65489C (fr) 1949-06-15
GB630692A (en) 1949-10-19
BE446845A (fr)
FR885191A (fr) 1943-09-07
NL70087C (fr) 1951-08-15
GB616358A (en) 1949-01-20
CH231618A (de) 1944-03-31
GB632169A (en) 1949-11-17
DE869223C (de) 1953-03-02
FR53545E (fr) 1946-03-04
FR53543E (fr) 1946-03-04
US2595931A (en) 1952-05-06
CH256781A (de) 1948-08-31
US2483889A (en) 1949-10-04
DE878971C (de) 1953-04-23

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