US1941068A - Radiosignaling - Google Patents

Radiosignaling Download PDF

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Publication number
US1941068A
US1941068A US653236A US65323633A US1941068A US 1941068 A US1941068 A US 1941068A US 653236 A US653236 A US 653236A US 65323633 A US65323633 A US 65323633A US 1941068 A US1941068 A US 1941068A
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United States
Prior art keywords
frequency
current
voltage
phase
modulation
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Expired - Lifetime
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US653236A
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English (en)
Inventor
Edwin H Armstrong
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Individual
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Individual
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Priority to NL44759D priority Critical patent/NL44759C/xx
First worldwide family litigation filed litigation Critical https://patents.darts-ip.com/?family=24620029&utm_source=google_patent&utm_medium=platform_link&utm_campaign=public_patent_search&patent=US1941068(A) "Global patent litigation dataset” by Darts-ip is licensed under a Creative Commons Attribution 4.0 International License.
Application filed by Individual filed Critical Individual
Priority to US653236A priority patent/US1941068A/en
Application granted granted Critical
Publication of US1941068A publication Critical patent/US1941068A/en
Priority to FR771090D priority patent/FR771090A/fr
Priority to DEA72334D priority patent/DE621204C/de
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B14/00—Transmission systems not characterised by the medium used for transmission
    • H04B14/002—Transmission systems not characterised by the medium used for transmission characterised by the use of a carrier modulation
    • H04B14/006—Angle modulation
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03C—MODULATION
    • H03C3/00—Angle modulation
    • H03C3/38—Angle modulation by converting amplitude modulation to angle modulation
    • H03C3/40—Angle modulation by converting amplitude modulation to angle modulation using two signal paths the outputs of which have a predetermined phase difference and at least one output being amplitude-modulated

Definitions

  • This invention relates to a method of signaling in radio communication by means of the modulation of the frequency of the transmitted wave.
  • the object of the invention is to provide a system in which the frequency and phase of the current generated by the master oscillator of the transmitter remains fixed and the frequency variation of the transmitted wave is obtained by phase shifting and frequency correction devices as hereinafter described.
  • a further object of the invention is to provide a system in which both the production of the variable frequency currents of the transmitted wave and the translation of the variations of frequency of the received wave to reproduce the signaling currents are accomplished by aperiodic means,
  • Fig. I illustrates the general arrangement of the transmitting system.
  • Fig. II illustrates "the general arrangement of the receiving system.
  • Figs. III and IV illustrate certain diagrams showing the phase relations in the system as hereinafter set forth.
  • 1 represents a constant frequency oscillator, preferably crystal controlled
  • 2 an amplifier of the output of this oscillator with a resistance 3 in its plate circuit which is small in comparison with the impedance of the tube.
  • 4 and 5 are likewise amplifiers of the output of the master oscillator 1.
  • 6 is a transformer for differentially modulating the plate voltages of the tubes 4 and 5 by the signaling current which is applied to the primary of the transformer.
  • 7 and 8 are condensers shunting the two halves of the secondary of the transformer 6.
  • 9 and 10 are inductances whose impedance for the frequency of the oscillator is small compared to the impedance of the tubes 4 and 5.
  • 11 is a small inductance whose natural frequency is high compared to the frequency of the oscillator. It is coupled differentially to the coils 9 and 10.
  • 12 is an amplifier for amplifying the output of tubes 4 and 5. Its plate is connected as shown to an adjustable point on the resistance in the plate circuit of the amplifier 2. The combined outputs of the tubes 2 and 12 are supplied to an amplifier 15, 16 whose output passes thru a current limiter 17, filter 18, and to a frequency multiplier 19, power amplifier 20 and antenna 22.
  • the operation of the system is as follows: The E. M. F. of the oscillator output is impressed upon the grid of the amplifier 2 and a current of the same frequency is thereby created in the plate circuit of the amplifier. This current is in phase with the E. M. F. impressed upon the grid since the impedance in the plate circuit is pure resistance and the frequency which is chosen to start with is such that tube capacity is of negligible importance. across the plate resistance and the phase of this voltage is 180 from that of the E. M. F. impressed upon the grid.
  • induced in coil 11 by the current in either 9 or 10 is 90 out of phase with the E. M. F. applied to the grids of tubes 2, 4 and 5.
  • the E. M. F. in coil 11 may be either 90 ahead or 90 behind the E. M. F. applied to the grids of these tubes, depending upon the polarity of coils 9 and 10 with respect to coil 11.
  • This coil is differentially coupled to coils 9 and 10 so that when the plate circuits of tubes 4 and 5 are not being modulated the E. M. F. induced in the coil is zero.
  • A represents the modulating current in transformer 6
  • B the plate voltages (of modulation frequency) of tubes 4 and 5
  • C the vector combinations of radio frequency voltages produced in the plate circuit of tube 2.
  • the action of the system a, 5, 12 is alternately to advance and to retard the phase of the E. M. F. applied to the grid of tube 15 with respect to the phase of the constant frequency oscillator 1.
  • the frequency of the E. M. F. applied to the grid of tube 15 is alternately increased above and decreased below the frequency of the constant frequency oscillator 1.
  • the rate of change is in accordance with the frequency of the modulating current in the transformer 6 and the extent of the change depends on the ratio of the E. M. F. produced across the resistance 3 by the tube 12 to the E. M. F. produced across it by the tube 2.
  • the angle of phase shift which is produced must be inversely proportional to the frequency of the modulating E. M. F.
  • a second amplifying stage 30, 31 raises the corrected voltage to a level suflicient to operate the modulating system.
  • any desired frequency variation may be produced.
  • phase shift of the transmitted wave for the highest frequency of modulation be of the order of 45. Therefore the number of multiplications should be sufficient to produce at least this amount of phase shift at obtaining straight line rectification.
  • the highest modulation frequency Assuming, for example, that the lowest frequency of modulation is 39 cycles per second and that there is a maximum phase shift of 30, then for 78 cycles there will be a phase shift of 15 degrees and for 156 cycles a phase shift of 75 etc. until for a 5000 cycle modulating current the phase shift will be only .234 degrees.
  • a phase shift of at least 45 in the transmitted wave at the h'ghest modulating frequency is required in order to produce what corresponds in amplitude signaling to 100% modulation. Therefore the .234 degree phase shift must be multiplied about 192 fold to produce a 45 phase shift in the transmitted wave.
  • variable frequency E. M. F. appled to the grid of tube is amplified by that tube and the amplifier 16, passed thru a current limiter 1'7, a filter 18 to remove harmonics, multiplied any desired number of times by the frequency multiplier 19 and then amplified by the power amplifier 20 whose output feeds the antenna 22.
  • Fig. 2 there is illustrated a type of receiver previously described in my pending application Serial No. 192,320, filed May 18, 1927, for Radio telephone signalling.
  • 32 represents the receiving antenna, 33 an amplifier of the received frequency, 34 an oscillator, and 35 the first rectifier of a superheterodyne receiving system.
  • 36 represents the intermediate frequency amplifier and 3'? a current limiter for removing amplitude fluctuations from the intermediate frequency current.
  • 38 is a filter for removing undesired harmonics created by the current limiter and 39 is an amplifier for the intermediate frequency current to raise it to a sufiicient level to produce straightline rectification by the detectors 46, 47.
  • the output of the amplifier 39 is delivered to a selective system consisting'of two branch circuits 40, 42, 44 and 41, 43, 45 which are connected respectively to the two detectors 46, 47 as shown. These detectors are biased to cutoff for the purpose of
  • the resistances 40 and 41 are made sufficiently large with respect to the reactances of the capacity inductance combinatons 42, 44 and 43, 45 to insure the current in the circuit remaining constant thruout the range of variation of the intermediate frequency.
  • the values of capacity and inductance are so chosen that the reactance of one branch is zero at some frequency slightly below the lowest frequency existing in the interfor each branch are equal to each other. .48, 49
  • indicating instrument 56 for thepurpose of indicating when the balance is obtained.
  • 52, 53, 54 and 55 are the usual bypass condensers.
  • 57 represents the reeciving telephone or other signaling device connected to the secondaries of the transformers 48, 49 which are so poled that rectified currents resulting from amplitude variations in the intermediate frequency current produce opposing voltages in the secondary windings wh le rectified currents resulting from freof the capacity and inductance in the other branch circuit.
  • the combined output currents are shown by curve 0, which represents the current in the indicator 56.
  • the present arrangement operates substant ally in the same manner as the arrangement previously filed except that in the present case the selecting system for translating variations in frequency into variations in amplitude is carried out by two branch circuits each containing capacity and inductance instead of in a single circuit containing two capacities and a single inductance.
  • This difficulty may be avoided in one of two ways.
  • One is to continue the multiplications of phase shift regardless of the resulting frequency until the desired number of revolutons are obtained and then to heterodyne the L40 resulting frequency down to the desired value, amplify it and transmit it.
  • the other is to multiply the frequency tosome value less than the frequency which it is desired to transmit, heterodyne it down to some submultiple of the transmitting frequency, multiply it up again to the transmitting frequency, amplify it and transmit it.
  • the choice of the frequency to which the heterodyning should be carried is determined by the number of revolutions of phase shift which are desired.
  • the non-reactive points of the two capacity inductance combinations are chosen farther apart and the rest of the system correspondingly designed to accommodate the higher modulation frequencies. Otherwise the action of the system for the transmission of television modulations is the same as for sound modulations.
  • a system of radio communication including a transmitter and a receiver, in which signaling is accomplished by frequency modulation of the transmitted waves, means at the transmitter operating aperiodically for creating a wave the frequency of which is modulated in accordance with the signals to be transmitted, means at the receiver operating aperiodically for translating the frequency modulations of the received wave into amplitude modulations, and means for detecting said amplitude modulations, to derive therefrom the transmitted signal.
  • a transmitter comprising a source or" current of constant frequency, a source of signaling current, and aperiodic means for deriving from said sources a current of variable frequency, the
  • said aperiodic means having the characteristic of varying the phase of the said derived current directly proportionally to the amplitude of the modulating current and inversely proportionally to the frequency of said current.

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  • Engineering & Computer Science (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Signal Processing (AREA)
  • Amplitude Modulation (AREA)
US653236A 1933-01-24 1933-01-24 Radiosignaling Expired - Lifetime US1941068A (en)

Priority Applications (4)

Application Number Priority Date Filing Date Title
NL44759D NL44759C (fr) 1933-01-24
US653236A US1941068A (en) 1933-01-24 1933-01-24 Radiosignaling
FR771090D FR771090A (fr) 1933-01-24 1934-01-24 Procédé et appareil de radiocommunication
DEA72334D DE621204C (de) 1933-01-24 1934-01-24 Verfahren zur Erzeugung eines frequenzmodulierten Stromes

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US653236A US1941068A (en) 1933-01-24 1933-01-24 Radiosignaling

Publications (1)

Publication Number Publication Date
US1941068A true US1941068A (en) 1933-12-26

Family

ID=24620029

Family Applications (1)

Application Number Title Priority Date Filing Date
US653236A Expired - Lifetime US1941068A (en) 1933-01-24 1933-01-24 Radiosignaling

Country Status (4)

Country Link
US (1) US1941068A (fr)
DE (1) DE621204C (fr)
FR (1) FR771090A (fr)
NL (1) NL44759C (fr)

Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2433093A (en) * 1943-04-27 1947-12-23 Rca Corp Amplitude modulation adapter system
US2435736A (en) * 1941-02-13 1948-02-10 Zenith Radio Corp Frequency modulated picture receiver
US2448558A (en) * 1942-11-17 1948-09-07 Edwin K Stodola Modulation networks
US2601340A (en) * 1949-05-09 1952-06-24 Edward J Stachura Frequency discriminator
US2841785A (en) * 1946-05-08 1958-07-01 Jr Frederic Cunningham Target simulating signal generator
US2871348A (en) * 1954-06-15 1959-01-27 Westinghouse Electric Corp Discriminator circuit
FR2534425A1 (fr) * 1982-10-08 1984-04-13 Thomson Csf Dispositif de modulation de phase ou de frequence a faible indice de modulation
US6032028A (en) * 1996-04-12 2000-02-29 Continentral Electronics Corporation Radio transmitter apparatus and method

Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2435736A (en) * 1941-02-13 1948-02-10 Zenith Radio Corp Frequency modulated picture receiver
US2448558A (en) * 1942-11-17 1948-09-07 Edwin K Stodola Modulation networks
US2433093A (en) * 1943-04-27 1947-12-23 Rca Corp Amplitude modulation adapter system
US2841785A (en) * 1946-05-08 1958-07-01 Jr Frederic Cunningham Target simulating signal generator
US2601340A (en) * 1949-05-09 1952-06-24 Edward J Stachura Frequency discriminator
US2871348A (en) * 1954-06-15 1959-01-27 Westinghouse Electric Corp Discriminator circuit
FR2534425A1 (fr) * 1982-10-08 1984-04-13 Thomson Csf Dispositif de modulation de phase ou de frequence a faible indice de modulation
US6032028A (en) * 1996-04-12 2000-02-29 Continentral Electronics Corporation Radio transmitter apparatus and method

Also Published As

Publication number Publication date
NL44759C (fr)
FR771090A (fr) 1934-09-29
DE621204C (de) 1935-11-02

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