US2531866A - Mixing detector circuit for detecting frequency-modulated oscillations - Google Patents

Mixing detector circuit for detecting frequency-modulated oscillations Download PDF

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Publication number
US2531866A
US2531866A US732A US73248A US2531866A US 2531866 A US2531866 A US 2531866A US 732 A US732 A US 732A US 73248 A US73248 A US 73248A US 2531866 A US2531866 A US 2531866A
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United States
Prior art keywords
control grid
grid
cathode
anode
tube
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Expired - Lifetime
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US732A
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English (en)
Inventor
Adrianus Johannes Wilhel Marie
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Hartford National Bank and Trust Co
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Hartford National Bank and Trust Co
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    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03D—DEMODULATION OR TRANSFERENCE OF MODULATION FROM ONE CARRIER TO ANOTHER
    • H03D3/00—Demodulation of angle-, frequency- or phase- modulated oscillations
    • H03D3/02—Demodulation of angle-, frequency- or phase- modulated oscillations by detecting phase difference between two signals obtained from input signal
    • H03D3/22—Demodulation of angle-, frequency- or phase- modulated oscillations by detecting phase difference between two signals obtained from input signal by means of active elements with more than two electrodes to which two signals are applied derived from the signal to be demodulated and having a phase difference related to the frequency deviation, e.g. phase detector

Definitions

  • the oscillations to be detected are supplied to two coupled circuits, the second of which is tuned to the central frequency of the said oscillations.
  • the voltages generated across the two circuits exhibit a phase-shift dependent on the frequencies of the oscillations to be detected.
  • These voltages are supplied to two control grids of a mixing tube so that the anode circuit of this tube is traversed by a current having a low-frequency component which, to a first approximation, is proportional with the frequency deviation of the oscillations to be detected.
  • The'object of the present invention is to provide a mixing detector circuit the operation of which is based on a different principle, but which also comprises a tube having two control grids. It affords the advantage that simpler circuit elements will sufiice (notably there is no need for utilising two coupled circuits) while the sensitivity and the linearity satisfy high requirements.
  • the oscillations to be detected are supplied to the first of the two said control grids, which grid is operated in class AB or class B condition.
  • a pulsatory voltage which is supplied to the second control grid in such manner that, a constant time after the passage of current by the first grid, the second grid operating in class B or class C condition also allows the passage of current.
  • a tube shown in Figure 1 comprises two control grids 2 and 3.
  • the oscillations to be detected are supplied to the control grid 2 through a conductor 4.
  • a screen or accelerating grid 5- which, as long as the control grid 2, which is operated in class AB or B condition, does not allow the passage of current, conveys a substantially constant current.
  • the pulsatory voltage set up at grid 5 is supplied, via a retarding network 6, to the second control grid 3 of the tube I, which operates in class B or class 0 condition.
  • the voltage set up at the grid 2 is designated a.
  • This grid allows the passage of current at the moment I) so that the current flowing to the grid 5 and indicated by the curve 2' rapidly decreases and attains a final value 7'.
  • a pulsatory voltage is set up at this grid which is applied to the second control grid 3 of the tube a time t afterwards.
  • the grid 3 will thus also pass current at the moment 0. Consequently, the tube i is only traversed by anode current between the moments c and d.
  • the time ed bears a linear relationship to the periodic time of the oscillations to be detected.
  • the figure shows that, if the time t has a value somewhat smaller than half of the shortest momentary periodic time of the frequency-modulated incoming signal, the anode current of the tube I has a modulation depth or approximately Consequently, a high sensitivity may be ensured by including a resistance of sufficiently high value in the anode circuit of the tube l.
  • the present invention is not limited to the example shown in the figure and notably it is possible for the pulsatory voltage to be supplied to the grid 3 of tube I to be derived, for example, from the anode circuit of an auxiliary tube, whose control grid, which is adjusted in class AB or B, is supplied with the oscillations to be detected.
  • a pulsatory voltage is derived from a screen-grid following the grid 2 of tube I, which pulsatory voltage is supplied to a phase-inverting tube or transformer, whereupon the voltage inverted in phase opens the grid 3 of. tube 1 a constant time t later than the moment at which the grid 2 of tube l allows the passage of current.
  • a circuit arrangement for demodulating a source of frequency modulated signals comprising, a thermionic discharge tube having a oathode, anodefirst and second control grids and a screen electrode between the cathode and the first control grid, means to supply s urce of signais to the first control grid-cathode l-cuit of the said thermionic discharge tube :7 leans to derive a pulsed voltage at the-screen ectrode cathode circuit of the said thermionic discharge tube proportional to the modulation of the signals, said latter means comprising a source of bias voltage applied to the first control grid of the said thermionic discharge tube having a value at which first control grid current will flow for a time proportional to the modulation of the signal, a time delay network, and means to couple the screen electrode to the second control grid through the said time delay network.
  • a circuit arrangement for demodulating a source of frequency modulated signals comprising, a thermionic discharge tube having a cathode, anode, first and second control grids and a screen electrode between the cathode and the first control grid, means to supply the source of signals to the first control grid-cathode circuit of the said thermionic discharge tube, means to derive a pulsed voltage in the screen electrode cathode circuit of the said thermionic discharge tube proportional to the modulation of the signals, said latter means comprising a source of class B bias voltage applied.
  • a circuit arrangement for demodulating a source of frequency modulated signals comprising, a thermionic discharge tube having a cathode, anode, first and second control grids and a screen electrode between the cathode and the first control grid, means to supply the source of signals to the first control grid-cathode circuit of the said thermionic discharge tube, means to derive a pulsed voltage in the screen electrode cathode circuit of the said thermionic discharge tube proportional to the modulation of the signals and having a pulse duration less than one half a semicycle of the signals, said latter means comprising a source of class B bias voltage applied to the first control grid of the said thermionic discharge tube having a value at which first control grid current will fiow for a time proportional to the modulation of the signal, a resistance-capacitance network, a source of class B bias voltage applied to the second control grid of the said thermionic discharge tube, and means to couple the screen electrode to the second control grid through the said resistance-capacitance net
  • a circuit arrangement for detecting a frequency modulated wave comprising a thermionic discharge tube having a cathode, an anode and first and second control grids interposed in the order named between the cathode and anode and having an accelerating electrode, means to apply the frequency modulated wave to said first control grid, means to apply biasing potentials to said first and second control grids to cut off electron current flow from the cathode to the anode through the said control grids for a time period less than a period of the mean frequency value of said frequency modulated wave, means to derive a pulsed voltage from said accelerating electrode, means to apply said pulsed voltage to said second control grid to render the same electron conductive a fixed time interval subsequent to electron conduction through said first control grid, and means to derive a de-- tected wave from said anode.
  • a circuit arrangement for detecting a frequency modulated wave comprising a thermionic discharge tube having a cathode, an anode and first and second control grids interposed in the order named between the cathode and anode and having an accelerating electrode, means to apply the frequency modulated wave to said first control grid, means to apply a biasing potential to said first control grid to cut oil electron flow from the cathode to the anode through said first control grid for a time period within one half period of the mean frequency value of the frequency modulated wave, means to apply a biasing potential to said second control grid to cut oif electron current flow from the cathode to the anode through said second control grid for a time period between one-half period and a full period of the mean frequency value of the frequency modulated wave, means to derive a pulse voltage from said accelerating electrode, means to apply said pulse voltage to said second control grid to render the same electron conductive a fixed time interval subsequent to electron conduction through said first control grid, and means to derive a detected
  • a circuit arrangement for detecting a frequency modulated wave comprising a thermionic discharge tube having a cathode, an anode and first and second control grids interposed in the order named between the cathode and anode and having an accelerating electrode, means to apply the frequency modulated wave to said first control grid, means to apply a biasing potential to said first control grid to out ofi electron current flow from the cathode to the anode through said first control grid for a time period within one half period of the mean frequency value of the frequency modulated wave, means to apply a biasing potential to said second control grid to cut off electron current flow from the cathode to the anode through said second control grid for a time period between one half period and a full period of the mean frequency value of the frequency modulated wave, means to derive a pulse voltage from said accelerating electrode, means to apply said pulse voltage to said second control grid to render the same conductive a time interval equal to approximately one-half period of the highest frequency of said frequency modulated wave subsequent to electron conduction

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  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • X-Ray Techniques (AREA)
  • Amplitude Modulation (AREA)
  • Other Investigation Or Analysis Of Materials By Electrical Means (AREA)
US732A 1947-01-14 1948-01-06 Mixing detector circuit for detecting frequency-modulated oscillations Expired - Lifetime US2531866A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
NL266789X 1947-01-14

Publications (1)

Publication Number Publication Date
US2531866A true US2531866A (en) 1950-11-28

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Application Number Title Priority Date Filing Date
US732A Expired - Lifetime US2531866A (en) 1947-01-14 1948-01-06 Mixing detector circuit for detecting frequency-modulated oscillations

Country Status (7)

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US (1) US2531866A (fr)
BE (1) BE479537A (fr)
CH (1) CH266789A (fr)
DE (1) DE832306C (fr)
FR (1) FR959556A (fr)
GB (1) GB643290A (fr)
NL (1) NL66481C (fr)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2844720A (en) * 1954-12-06 1958-07-22 Radio Frequency Lab Inc Frequency shift discriminator

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE969436C (de) * 1951-04-26 1958-06-04 Lorenz C Ag Anordnung zur Demodulation frequenz- oder phasenmodulierter Schwingungen

Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2087429A (en) * 1935-06-06 1937-07-20 Rca Corp Phase and frequency modulation wave receiving system
US2239757A (en) * 1940-01-02 1941-04-29 Rca Corp Signal detecting system
US2263615A (en) * 1940-04-06 1941-11-25 Rca Corp Frequency modulation detector
US2284444A (en) * 1940-08-27 1942-05-26 Bell Telephone Labor Inc Demodulation circuit
US2296090A (en) * 1942-09-15 Frequency modulation receiver
US2343263A (en) * 1942-05-06 1944-03-07 Hazeltine Corp Carrier-signal frequency detector
US2462110A (en) * 1941-12-19 1949-02-22 Int Standard Electric Corp Demodulation of time-modulated electrical pulses

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2273771A (en) * 1941-04-10 1942-02-17 Rca Corp Frequency modulated carrier detector

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2296090A (en) * 1942-09-15 Frequency modulation receiver
US2087429A (en) * 1935-06-06 1937-07-20 Rca Corp Phase and frequency modulation wave receiving system
US2239757A (en) * 1940-01-02 1941-04-29 Rca Corp Signal detecting system
US2263615A (en) * 1940-04-06 1941-11-25 Rca Corp Frequency modulation detector
US2284444A (en) * 1940-08-27 1942-05-26 Bell Telephone Labor Inc Demodulation circuit
US2462110A (en) * 1941-12-19 1949-02-22 Int Standard Electric Corp Demodulation of time-modulated electrical pulses
US2343263A (en) * 1942-05-06 1944-03-07 Hazeltine Corp Carrier-signal frequency detector

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2844720A (en) * 1954-12-06 1958-07-22 Radio Frequency Lab Inc Frequency shift discriminator

Also Published As

Publication number Publication date
CH266789A (de) 1950-02-15
NL66481C (fr)
DE832306C (de) 1952-02-21
GB643290A (en) 1950-09-15
BE479537A (fr)
FR959556A (fr) 1950-03-31

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