US2483315A - Superheterodyne receiver - Google Patents

Superheterodyne receiver Download PDF

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Publication number
US2483315A
US2483315A US661523A US66152346A US2483315A US 2483315 A US2483315 A US 2483315A US 661523 A US661523 A US 661523A US 66152346 A US66152346 A US 66152346A US 2483315 A US2483315 A US 2483315A
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US
United States
Prior art keywords
circuit
frequency
amplifier
filter
carrier
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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
US661523A
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English (en)
Inventor
Groot Folkert Albert De
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Hartford National Bank and Trust Co
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Hartford National Bank and Trust Co
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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 US2483315A publication Critical patent/US2483315A/en
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    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03J—TUNING RESONANT CIRCUITS; SELECTING RESONANT CIRCUITS
    • H03J7/00—Automatic frequency control; Automatic scanning over a band of frequencies
    • 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

Definitions

  • the damping. of the resonant circui-ts is. reducedby means of feed back coupling via one or more of the discharge systems belong ing to: the amplifier,. or by a negative resistance" appearing between: two electrodes at one or more of these discharge systems.
  • Such accentuati'on ispreferably accomplished by means of a filter comprising one or' moreresonant circuits the damping 01fv which is reduced by an amplifier.
  • the invention more particularly relates to a form of construction of the above de'scribed' superheterodyne receiver wherein all the side: band frequencies are attenuated at least approxi- 10 Claims.
  • (Cl. lie-iii) mately inproportion" to the attenuation of the carrier wave;- Accor'ding to the invention, to this end the receivedintermediate frequency oscillations corresponding to the received carrier frequency and side-band frequency signals are transferred directly to the amplifier which reduces the damping of'the' resonant circuit or cir-'- cuitsof thesharpfilter, and supplied indirectly to thefilter viaithis' amplifier, while the resulting 2 gilitenoy oscillations were supplied directly to the Consequentl'y, it is also" desirable that the 0s c llat ons of intermediate-frequency corresponding to the ca rrier wave selected by the filter should be derived froin th whole of the inter- Ir ed ate treq icncy o
  • agitate-gents circuit arrangee r in at least one stage time a g na, bo nine trite ance-frequency 0sc ll'at ohs suppli'f dire t6 the afiiplifii and git; oscillations selected t3, hie filter are am ii The fee v'ed ififrfiie'dijdtefrediiefic i ⁇ o cillation's" prei'iatiy M p I chjrir'iliii series with theoi tpiit rni filter; this series" connection being" co led" to the input electrodes of a discneigj sir camping or 1 rue interni'ai te'neqiieiics osciiittioiis ma alternat vely bet'ra sinittditc one of the controi grids or a (r sensystem with the
  • the damp ing reducing amplifier is preferably firovided with meat eied beck ⁇ an this in siic'fi manner that qenipinetr the fi ter; not reduced y "ck" itself.
  • step results instatility of tl'ie circuit' arrangement so that there is no an er of seir-xc'itatizijn ir'i' trie daseof's'trfig reduction of damp ng of me filtefi V o If the received inlieiiifedijf-frediiency oscillla'tio'nsf are transferred fidudmaster y to an impedance manne iii fcivi-ii'gcHannel-in series v'i'lith' the detect tei iiiii'ia'ls of: the filter, it frequeiim' OECuYS tHaf-fil accentiiatiofi of theside- 3 bands is not wholly symmetric with respect to the carrier wave.
  • the influence of the said parasitic coil 8 comprises a core of high-frequency iron which has themagnetising coil l8 arranged on it.
  • the-side-band frequencies of the intermediatefrequency signal are strongly attenuated with respect to the. carrier wave, thus avoiding the danger thatwith selective fading an apparent capacities upon the resonance curve of the filter h is neutralized.
  • the figure shows the intermediate-frequency portion of a receiver comprising a sharp filter for the selection of the carrier wave, a control voltage for the automatic frequency control being produced with the aid of a selective network which has two control rectifiers connected to it, and the intermediate-frequency carrier wave being maintained within the range of frequencies selected by the filter due to the tuning or the sharp filter being acted upon by the said control voltage.
  • the filter also forms part of the above-mentioned selective network.
  • the intermediate-frequency portion of the receiver comprises an intermediate-frequency amplifying tube i which is coupled to the control grid circuit of a discharge tube 4 via a resonant circuit 2 tuned to the intermediate-frequency and an impedance comprising a coupling coil 3.
  • the latter is in series with a filter whichis-constituted by a circuit the damping of which is reduced and which is constituted by a condenser i3 and two series-connected coils l and 8. Consequently, the received intermediate-irequency oscillations are transferred indirectly to the filter 5.
  • the damping of circuit 5 is reduced by being connected in three-point arrangement to the discharge tube fl.
  • the anode circuit of the discharge tube 4 includes a resonant circuit it which is tuned to the ,intermediatefrequency and which is coupled by capacitive means to a diodedetector H, th audio-frequency output voltage of which is suppliedto an audio-frequency amplifier (not shown) V f
  • the circuit 2 has, in addition, coupled to it a circuit 12 which is'falso'tun'ed to the intermediate-frequency and which. has connected to it two pushpull connected control rectifiers (diodes) l3 and 14.
  • The, centre of circuit [2 is connected to the centre ofthe output resistance I5 of the two diodes l3 and, i4 via a coupling coil I 5 which is inductively coupled to the intermediate-frequency circuit Ill.
  • the carrier wave may thus, for example, be amplified 10 to 15 times with respect to the amplification of the side-band frequencies;
  • the tuning frequency of the circuit 5 should always correspond within narrow limits to the intermediate-frequency carrier wave. This conformity is ensured by the automaticfrequency contro1 since when a deviation occurs between thesaid frequencies there is produced across the resistance 5 a control voltage of suitable polarity-whichchanges the inductance of the coil 8 to such extent that the tuning frequency of the circuit-5 isapproxirier-wave frequency.
  • control Due to the circuit 5 forming part of the network for the production of the control voltage, the control is highly sensitive to small variations in frequency.
  • the coupling 'coil 3 iscoupled to the intermediate-frequency circuit 2 not only inductively but also by capacitative means via a variable condenser 19.
  • avariable condenser 2&2 is connected in parallel with the series-connect1on of the coupling coil 3 and the circuit 5.
  • termediate frequency circuit 2 and the coil 3 and between the coupling coil 3 and earth respectively are connected in parallel with the condensers l9 and 23 respectively.
  • these parasitic capacities could bring about asymmetry in the resonance curve of the filter so that the lateral hands would no longer be symmetrically attenuated With respect to the intermediate-frequency carrier wave.
  • this influence of the parasitic capacities on the resonance curve is neutralizedby the arrangement of condensers l9 and 2E. of at least one of these condensers it is possible to obtain a filter exhibiting a symmetric resonance curve, due to which distortion of the signal is avoided.
  • An amplifier circuit arrangement particularly for use in a receiver for receiving signal voltages of carrier and sideband frequencies, comprising an am lifier having an input circuit and an output uliClllt, filter circuit elements sharply tuned to a frequency corresponding to said carrier frequency, means to apply a first signal voltage having frequency components corresponding to said carrier and said sideband frequencies to the input circuit of said amplifier, means to couple said filter circuit elements to said amplifier to derivea second signal voltage of frequency corresponding to said carrier frequency,.means to apply said second si nal voltage to the input circuit of said amplifier and to reduce the damping of said filter, and means coupled to. the output circuit of said amplifier to derive an output voltage comprising said first signal voltage and said second signal voltage.
  • An amplifier circuit arrangement particularly for use in a receiver for receiving signal voltages of carrier and sideband frequencies, comprising a. resonant circuit for translating a first signal v -tage having frequency components corresponding to said carrier and said sideband frequencies, an amplifier having an input circuit and an output circuit, a filter circuit sharply tuned to a frequency corresponding to said carrier frequency Ts-cans to couple said resonant circuit and said filter circuit in series 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 By means of a suitable adjustment 6 couple said filter circuit to said amplifier to derive and apply to theinput circuit of said amplifier a second signal voltage'of frequency corresponding to said carrier frequency to reduce the damping of saidfilter,- and means coupled to the output circuit of said amplifier to derive an output voltage coniprising'said first signal voltage and saidsecond signal voltage and having carrier frequency components relative to sideband fre quency components greater than the carrier frequency component of said first signal voltage.
  • An amplifier-circuit arrangement particularly for use in a receiver for receiving signal voltages of carrier and sideband frequencies, comprising a resonant circuit for translating a first signal voltage having frequency components corresponding to said carrier and said sideband frequencies, an electron discharge tube amplifier having a cathode, a first control grid, ascoond control grid and an anodeyafilter circuit tuned to frequency corresponding to carrier frequency, means to couple said reson nt ircuit to the first control grid of said amplifier tulle to.
  • An amplifier circuit arrangement particularly for use in a receiver for receiving signal voltages of carrier and sideband frequencies, comprising a resonant circuit for translating a first signal voltage having frequency components corresponding to said carrier and said sideband frequencies, an amplifier having an input circuit and an output.
  • An amplifier circuit arrangement particularly for use in a receiver for receiving signal voltages of carrier and sideband frequencies, comprising a first amplifying stage, a resonant circuit for translating a first signal voltage having frequency components corresponding to said carrier and said sideband frequencies inductively coupled to said first amplifying stage, a first capacitor coupling said resonant circuit and said first amplifier stage, an amplifier having an input circuit and an output circuit, a filter circuit sharply tuned to a frequency corresponding to said carrier frequency, means to couple said resonant circuit and said filter circuit in series to the input circuit of said amplifier to apply a signal voltage of frequency corresponding to said carrier and sideband frequencies to said amplifier, a second capacitor connected in parallel with said series connected resonant circuit and said filter circuit, 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, and means coupled to the output circuit of said amplifier to derive an output voltage comprising said first signal voltage and said second signal voltage
  • An amplifier circuit arrangement particularly for use in a receiver for receiving signal voltages of carrier and sideband frequencies, comprising a resonant circuit for translating a first signal voltage having frequency components corresponding to said carrier and said sideband frequencies, an amplifier having an input circuit and an output circuit, a filter circuit, means coupled to said resonant circuit and the output circuit of said amplifier automatically to tune said filter sharply to a frequency corresponding to said carrier frequency, means to couple said resonant circuit 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 elements to said amplifier to derive a second signal voltage of frequency corresponding to said carrier frequency, means to apply said second signal voltage to the input circuit of said amplifier and to reduce the damping of said filter, and means coupled to the output circuit of said amplifier to derive an output voltage comprising said first signal voltage and said second signal voltage.
  • An amplifier circuit arrangement particularly for use in a receiver for receiving signal voltages of carrier and sideband frequencies, comprising a first amplifying stage, a resonant circuit for translating 3, first signal voltage having frequency components corresponding to said carrier and said sideband frequencies inductively coupled to said first amplifying stage, a first capacitor coupling said resonant circuit and said first amplifier stage, an amplifier having an input circuit and an output circuit, a filter circuit, means coupled to said resonant circuit and to the output circuit of said amplifier automatically to tune said filter circuit sharply to a frequency corresponding to said carrier frequency, means to couple said resonant circuit and said filter circuit in series to the input circuit of said amplifier to apply a signal voltage of frequency corresponding to said carrier and sideband frequencies to said amplifier, a second capacitor connected in parallel with said series connected resonant circuit and said filter circuia 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, and means
  • An intermediate frequency amplifier circuit arrangement particularly for use in a superheterodyne receiver for receiving signal voltages of carrier and sideband frequencies, comprising a resonant circuit for translating a first intermediate frequency signal voltage having frequency components corresponding to said carrier and said sideband frequencies, an electron discharge amplifier tube having a cathode, a control grid and an anode, a filter circuit comprising a first capacitor connected in parallel with a first inductor and a second inductor connected in series, means to couple said resonant circuit and the first inductor of said filter circuit in series between the control grid and cathode of said amplifier tube to apply a signal voltage of frequency corresponding to said carrier and sideband frequencies to said amplifier, means to couple said filter circuit to the cathode of said amplifier tube to apply to the control grid of said amplifier tube a second intermediate frequency signal voltage of frequency corresponding to said carrier frequency to reduce the damping of said filter circuit, means coupled to the anode of said amplifier tube and to said resonant circuit to derive a frequency control voltage, a
  • An intermediate frequency amplifier circuit arrangement particularly for use in a superheterodyne receiver for receiving signal voltages of carrier and sideband frequencies, comprising a resonant circuit for translating a first intermediate frequency signal voltage having frequency components corresponding to said carrier and said sideband frequencies, a first electron discharge amplifier tube having a cathode, a control grid and an anode, a filter circuit comprising a first capacitor connected in parallel with a first inductor and a second inductor connected in series, means to couple said resonant circuit and the first inductor of said filter circuit in series between the control grid and cathode of said first amplifier tube to apply a signal voltage of frequency corresponding to said carrier and sideband frequencies to said amplifier, means to couple said filter circuit to the cathode of said amplifier tube to apply to the control grid of said first amplifier tube a second intermediatefrequency signal voltage of frequency corresponding to said carrier frequency to reduce the damping of said filter circuit, a negative feedback resistor interposed between the first inductor of said filter circuit and the cathode of said

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  • Engineering & Computer Science (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Signal Processing (AREA)
  • Power Engineering (AREA)
  • Amplifiers (AREA)
  • Noise Elimination (AREA)
  • Circuits Of Receivers In General (AREA)
US661523A 1943-05-03 1946-04-12 Superheterodyne receiver Expired - Lifetime US2483315A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
NL254962X 1943-05-03

Publications (1)

Publication Number Publication Date
US2483315A true US2483315A (en) 1949-09-27

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Family Applications (1)

Application Number Title Priority Date Filing Date
US661523A Expired - Lifetime US2483315A (en) 1943-05-03 1946-04-12 Superheterodyne receiver

Country Status (7)

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US (1) US2483315A (pt)
BE (1) BE455596A (pt)
CH (1) CH254962A (pt)
DE (1) DE869222C (pt)
FR (1) FR903904A (pt)
GB (1) GB630321A (pt)
NL (1) NL75716C (pt)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2847567A (en) * 1955-06-10 1958-08-12 Hoffman Electronics Corp Automatic frequency control circuit
US3470485A (en) * 1965-12-28 1969-09-30 Nippon Electric Co Cascaded transistor amplifiers

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2162988A (en) * 1935-12-13 1939-06-20 Rca Corp Radio receiver
US2256070A (en) * 1940-07-09 1941-09-16 Rca Corp Radio receiving system

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2162988A (en) * 1935-12-13 1939-06-20 Rca Corp Radio receiver
US2256070A (en) * 1940-07-09 1941-09-16 Rca Corp Radio receiving system

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2847567A (en) * 1955-06-10 1958-08-12 Hoffman Electronics Corp Automatic frequency control circuit
US3470485A (en) * 1965-12-28 1969-09-30 Nippon Electric Co Cascaded transistor amplifiers

Also Published As

Publication number Publication date
NL75716C (pt)
FR903904A (fr) 1945-10-22
CH254962A (de) 1948-05-31
BE455596A (pt)
GB630321A (en) 1949-10-11
DE869222C (de) 1953-03-02

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