US2209273A - Carrier frequency system - Google Patents

Carrier frequency system Download PDF

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Publication number
US2209273A
US2209273A US257259A US25725939A US2209273A US 2209273 A US2209273 A US 2209273A US 257259 A US257259 A US 257259A US 25725939 A US25725939 A US 25725939A US 2209273 A US2209273 A US 2209273A
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US
United States
Prior art keywords
frequency
carrier
band
predetermined
receiver
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
US257259A
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English (en)
Inventor
Hills John Lionel
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.)
Fairey Aviation Co Ltd
Original Assignee
Fairey Aviation Co Ltd
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 Fairey Aviation Co Ltd filed Critical Fairey Aviation Co Ltd
Application granted granted Critical
Publication of US2209273A publication Critical patent/US2209273A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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Classifications

    • 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
    • H04B1/38—Transceivers, i.e. devices in which transmitter and receiver form a structural unit and in which at least one part is used for functions of transmitting and receiving
    • H04B1/40—Circuits
    • H04B1/50—Circuits using different frequencies for the two directions of communication
    • 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
    • H04B1/10—Means associated with receiver for limiting or suppressing noise or interference
    • H04B1/14—Automatic detuning arrangements
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B7/00—Radio transmission systems, i.e. using radiation field
    • H04B7/02—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04J—MULTIPLEX COMMUNICATION
    • H04J1/00—Frequency-division multiplex systems
    • H04J1/20—Frequency-division multiplex systems in which at least one carrier is angle-modulated

Definitions

  • the carrier n frequency of a transmitter-receiver station or each transmitter receiver station whilst arranged so as to be continuously variable within the predetermined frequency spectrum band, is normally maintained constant at. any fortuitous or predetermined frequency within said band, but is caused to vary when and only' when another transmitted carrier is received which produces at or before the second detector of the station an interference predetermined as to frequency and preferably also as to amplitude, which interference in the case of a speech-modulated carrier may be a heterodyne interference of, say, 5,000 cycles per second or even less.
  • the frequency is thus either increased or decreased so that the aforesaid frequency interference is automatically removed whereupon the frequency variation is discontinued so that the transmitted frequency is now caused to remain constant at a new value until a fur-ther interference may arise when the 25l process above described is repeated, and so on.
  • the speed of the .frequency shift is approin'mately proportional to the amplitude of the heterodyne interference so that ifa strong interfering signal is suddenly received the interference is the more quickly and more Widely removed than is the case of a relatively weak signal.
  • a plurality of signals may be simultaneously received which are automatically segregated into separate fixed frequency channels separated appropriately in accordance with their signal strength on the receiving. aerial. It is, of course, understood that the receiver is substantially aperiodic with respect to the predetermined frequency spectrum band.
  • the main object of the invention is to enable a carrier wave to be radiated continuously -wvithin a predetermined frequency spectrum band without preventing reception of one or more other carrier waves radiated Within said band and from stations at predetermined distances or of predetermined radiation strength, thus enabling an instrument to be produced which will immediately indicate when another transmitter is radiating at a frequency within the aforesaid band and within the rangeof sensitivity of the receiving instrument.
  • the instrument may thus be called a radio-proximity indicator for use for example by aircraft and by ships at sea.
  • the mean Wavelength will at the present time haveto be short, say i'lve metres. Since the range of such order of wavelengths is inherently short, apart from the power of the transmitter, the instrument according to the invention has great utility in connection with aircraft operating in the neighbourhood of for example an aerodrome or airport since it can provide to that airport or to aeroplanes within its vicinity an indication of one anothers proximity.
  • the system is entirely automatic in its warning and is such that the radiations from one craft cannot affect the'ability of that craft to receive signals or radiations from another craft.
  • Another important use of the invention may be in military operations where for example it is desired that communication should existbetween several units, one of which may be a commandingv 'unit from which orders are issued which are required to be received simultaneously by all the otherunits, which latter may reply at any time andeven interrupt the orders if necessary, Whilst furthermore the subordinate units can intercommunicate with each other;
  • Figure 1 is a block diagram illustrating the invention and the requirements thereof.
  • Fig. 2 is a diagram of a convenient arrangement for varying the transmission frequency and holding it at different values.
  • Fig. 3 is a circuit diagram illustrating how the braking devices shown in Fig. 1 may be supplied with current and,
  • Fig. 4 is a diagram showing an alternative aradapted to operate in accordance with the invenr tion.
  • the rectangle I represents conventionally a radio transmitter having a transmitting aerial 2 and a frequency control device 3 which is adapted under the conditions hereinbefore set forth to maintain the transmission frequency normally constant but to shift itwhen required.
  • the rectangle iv is amoptional frequency Wobbler unit .the purpose of which will be hereinafter described.
  • Fig. 1 further com-L transmitter.
  • Fig. 1 of the accompanying drawing is shownat II the interference beat selector or frequency l responsive device which is fed from theris't 'dtector '6. and which is connected to the frequencyy control unit 3 in the manner hereinafter specifically described.
  • the first detector 6 is aperiodic to -thepredetermined frequencygspectrum band but isv not responsive tov frequenciesi outside said band, whilst the intermediate fre.v i 3.0: quency amplifier 'I has a band pass characteristic responding to thedifference frequencies between carriers-from; .remote stations received by the.
  • thefrequency Wobbler unit 4 may coml- 50: prise merely a relatively minute' trimming condenser. havingan element adapted to be moved,
  • vSuch condenser y may be in parallel with ⁇ the variable tuning device in the uniti g3l-g1fl ⁇ he frequencywobble affected by the unit 4 is not 'criticaljand it isimmaterial whether. its
  • vrange varies slightly such asl at different settings ofy-thefmain frequency control unit which is 'con'- veniently a condenser.
  • the wobble rate should i603'. be either sub-audio or supersonic.l
  • aY varilable condenser incorporated in the transmission frequency determining unit 3.
  • This .condenser may be the main ⁇ or the: trimming condenserfof instead of a condenser any other means; may be provided vfor silently varying the transmitted frel 'quency within the predeterminedv frequency spectrum band, such forfinstance, as a distortableini IOfllductance coil forl an armature Ymovable relatively T clyavvspifingdriven: clock mechanismhaving a;
  • Such zero beat effect can' .L5-,readily be prevented by continuously wobbling' the transmission frequency over a rangev of say small pinion I4 and a large one I5.
  • the small pinion I4 meshes with a gear train comprising a large wheel I6 which meshes with a smaller. wheel II which is rigid with the moving element of the condenser or other variable tuning device I2.
  • the arrangement is therefore such that the motor I3 normally causes to rotate the moving element of the tunin'g'device I2r so :as to-,Lvary the frequency back and forth cyclically within the predetermined frequency spectrum band of the 'Ihelarge wheel l5 of the motor I3 drives the v exemplified soft iron toothed wheel I8 through n the multiplyinggear'train consisting, for example; of the system illustrated at I9.
  • the soft iron toothed wheel I 8 co-operates with an. elec- ⁇ tromagnetcomprising the yoke 26, polesZI and anode circuit. of a triode 23 in series with a limiting.
  • resistance 22a which is preferably adjustable, and lwith an anode battery 25;
  • tem is ⁇ designed.
  • the circuit 26 is tuned to be resonantv at 5,000cycles per second.
  • the cathv ode circuit of thevv diode 25a. is a delay bias; battery 2'I for preventing the diode from passing currentypuntilthe. heterodyne interference voltage attains a value. which will impair the intelligibility ofthe speech, received.
  • VBy such means the vsystem canv be made.' to ignore interfering signals which'fare of insufficient strength to lcause undesirable interference compatible with the purpose for which the systemis being used such for example as either. o'f the'purposes hereinbefore stated v by way fofexample.. ⁇
  • Thean'odev Yof the diode 25a is kconnected by.
  • the anode 2.0i the triode 23 includes in a balanced bridge arrangement the winding 29 of electric motor .(not shown) and resistances 3B, 3l, and 32.
  • This motor may be of any known and convenient type such as the motor of an electricity meter and it is preferably of the variable speed type and adapted to rotate or to operate the moving element of the variable tuning device I2 at a speed in accordance with the extent of energisation of the motor winding 2S which as will be appreciated varies in accordance with the voltage of the audible heterodyne which may arise at the first detector (Fig. 1) ⁇ except for the presence of the delay bias 2 of the diode 25a, which, as with the arrangement shown in Fig. 3, is provided for the purpose of preventing frequency shift unless the heterodyne interference volume is sufficient to impair speech intelligibility.
  • I claim: 1. The method of conference type carrier frequency intercommunication between a plurality of transmitter-receiver stations, which consists in continuously transmitting from each station a carrier at a frequency which is normally maintained constant somewhere within a predetermined frequency band, effecting aperiodically with respect to said predetermined band the supersonic heterodyne reception of the carrier of at least one of the other stations whilst using the local carrier for the heterodyning, and effecting an automatic shift of the local carrier frequency to another fixed place within said predetermined band when a received carrier produces a heterodyne interference of predetermined frequency.
  • the method of conference type carrier frequency intercommunication between a plurality of transmitter-receiver stations, which consists in continuously transmitting from each station a carrier at a frequency which is normally maintained constant somewhere within a predetermined frequency band, effecting aperiodically with respect to said predetermined band the supersonic heterodyne reception of the carrier of at least one of the other stations Whilst using the local carrier for the heterodyning, and effecting an automatic shift of the local carrier frequency to another fixed place within said predetermined band when a received carrier produces a heterodyne interference of predetermined frequency and predetermined amplitude.
  • a transmitter-receiver station for conference type carrierY frequency intercommunication comprising in combination a carrierwave transmitter having means adapted to vary the carrier frequency cyclically over a predetermined band, a supersonic heterodyne receiver arranged to utilize the local carrier as local oscillator said receiver having an intermediate frequency circuit substantially aperiodic to the range of intermediate frequency variation with respect to said .predetermined band, and means adapted automatically to actuate said carrier frequency varying means when a received carrier of frequency within said band produces a heterodyne interference of predetermined frequency so as to shift the carrier to another xed place within said band.
  • a transmitter-receiver station for conference type carrier frequency intercommunication comprising in combination a carrier wave transmitter having means adapted to vary the carrier frequency cyclically over a predetermined band, a supersonic heterodyne receiver arranged to utilize the local carrier as local oscillator, said receiver having an intermediate frequency circuit substantially aperiodic to the range of intermediate frequency variation with respect to said predetermined band, means for deriving from said receiver a voltage only when a received carrier of frequency Within said band produces a heterodyne interference of predetermined frequency and amplitude, and means adapted to actuate said carrier frequency varying means in response to said derived voltage and at a rate substantially proportional to said amplitude.
  • a transmitter-receiver station as claimed in claim '7 having additional means for continuously wobbling the carrier frequency over a range small compared with said predetermined band.
  • a transmitter-receiver station for conference type carrier frequency intercommunication com.- prising in combination a carrier wave transmitter having a tuning element which is normally fixed but is adapted to vary the carrier frequency cyclically over a predetermined band, a supersonic heterodyne receiver arranged to utilize the local carrier as local oscillator said receiver having an intermediate frequency circuit substantially aperiodic to the range of intermediate frequency variation with respect to said predetermined band, a resonant circuit for deriving from said receiver a voltage only when a received carrier of frequency within said band produces a heterodyne interference of predetermined frequency, and a motor adapted to actuate said tuning element to a new fixed position in response to said derived voltage.
  • a transmitter-receiver station for conference type carrier frequency intercommunication comprising in combination a carrier wave transmitter having a tuning element adapted to vary the carrier frequency cyclically over a predetermined band, a source of power tending to actuate said tuning element continuously, electroresponsive means for normally holding said tuning element against such actuation, a supersonic heterodyne receiver arranged to utilize the local carrier as local oscillator said receiver having an. intermediate yfrequency circuit substantially aperiodc to the range of intermediate frequency variation with respect to said predetermined band, means for deriving lfromsaid receiver an electrical effectfoniy when a received carrier of frequency within said band produces a heterodyne interference of predetermined frequency,. said electroresp'onsive holding means being energised from said deriving means. l
  • Atransmitter-receiver station for conference type carrier frequency intercommunication comprisingfn combination acarrier Wave transmitter having-means which are normally fixed but are adapted to fvary the carrier frequency" cyclicallyover a.
  • a supersonic heterodyne receiver arranged to utilize the local carrier as local oscillator said receiver having an intermediate frequency circuit substantially aperiodic to the range of intermediate frequency variation with respect tosaid predetermined band, means forv deriving from said receivera voltage.: onlyvwhen a received carrier of frequency Within said band produces a heterodyne interference of predetermined frequency, said/means comprising a biased -recti'er connected to some partofthe'receiver after the rst detector thereof with a load resistance and a circuit tuned to the predetermined interference frequency', and means adapted to actuate said carrier frequency varying means in respo-nse to said derived voltage so as to shift the transmission frequency toanother fixed place Within Said band.

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  • Engineering & Computer Science (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Signal Processing (AREA)
  • Selective Calling Equipment (AREA)
US257259A 1938-03-02 1939-02-18 Carrier frequency system Expired - Lifetime US2209273A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB6615/38A GB513161A (en) 1938-03-02 1938-03-02 Carrier frequency electric communication, signalling, indicating and remote control systems

Publications (1)

Publication Number Publication Date
US2209273A true US2209273A (en) 1940-07-23

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US257259A Expired - Lifetime US2209273A (en) 1938-03-02 1939-02-18 Carrier frequency system

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US (1) US2209273A (en(2012))
BE (2) BE417866A (en(2012))
FR (2) FR811767A (en(2012))
GB (1) GB513161A (en(2012))

Cited By (13)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2462069A (en) * 1942-05-07 1949-02-22 Int Standard Electric Corp Radio communication system
US2528632A (en) * 1947-03-13 1950-11-07 Smith Meeker Engineering Co Frequency control system
US2531398A (en) * 1943-02-25 1950-11-28 Farnsworth Res Corp Interference transmission system
US2532589A (en) * 1945-07-09 1950-12-05 Wu William Ieu-Liang Signal-seeking transceiver
US2585605A (en) * 1946-11-12 1952-02-12 Wallace Navigational system
US2617015A (en) * 1945-01-23 1952-11-04 Everard M Williams Panoramic system
US2648063A (en) * 1946-08-01 1953-08-04 Us Navy Transceiver system
US2708749A (en) * 1945-07-09 1955-05-17 Otto H Schmitt Panoramic transponder
US2885543A (en) * 1945-01-27 1959-05-05 Everard M Williams Automatic sweeping and jamming radio equipment
US2972119A (en) * 1954-01-12 1961-02-14 Gen Motors Corp Random sweep generator
US3160813A (en) * 1959-07-02 1964-12-08 Csf Tropospheric radio communication system
US3548312A (en) * 1966-11-17 1970-12-15 Philips Corp Device for transmitting an accurately determined fixed frequency with a tunable high frequency transmitter tube
US3916406A (en) * 1963-02-20 1975-10-28 Us Navy Jamming cancellation device

Families Citing this family (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2465341A (en) * 1941-02-08 1949-03-29 Int Standard Electric Corp Electric wave transmission system
US2635231A (en) * 1945-12-10 1953-04-14 Hal O Anger Interference reducing pulse echo signaling system
FR1147324A (fr) * 1956-04-09 1957-11-21 Csf Perfectionnements aux liaisons radioélectriques à grande distance et ultra-haute fréquence
US4135189A (en) * 1964-01-09 1979-01-16 Compagnie Generale De Telegraphie Sans Fil Random frequency radar system

Cited By (13)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2462069A (en) * 1942-05-07 1949-02-22 Int Standard Electric Corp Radio communication system
US2531398A (en) * 1943-02-25 1950-11-28 Farnsworth Res Corp Interference transmission system
US2617015A (en) * 1945-01-23 1952-11-04 Everard M Williams Panoramic system
US2885543A (en) * 1945-01-27 1959-05-05 Everard M Williams Automatic sweeping and jamming radio equipment
US2532589A (en) * 1945-07-09 1950-12-05 Wu William Ieu-Liang Signal-seeking transceiver
US2708749A (en) * 1945-07-09 1955-05-17 Otto H Schmitt Panoramic transponder
US2648063A (en) * 1946-08-01 1953-08-04 Us Navy Transceiver system
US2585605A (en) * 1946-11-12 1952-02-12 Wallace Navigational system
US2528632A (en) * 1947-03-13 1950-11-07 Smith Meeker Engineering Co Frequency control system
US2972119A (en) * 1954-01-12 1961-02-14 Gen Motors Corp Random sweep generator
US3160813A (en) * 1959-07-02 1964-12-08 Csf Tropospheric radio communication system
US3916406A (en) * 1963-02-20 1975-10-28 Us Navy Jamming cancellation device
US3548312A (en) * 1966-11-17 1970-12-15 Philips Corp Device for transmitting an accurately determined fixed frequency with a tunable high frequency transmitter tube

Also Published As

Publication number Publication date
FR811767A (fr) 1937-04-22
BE417866A (en(2012)) 1936-11-30
GB513161A (en) 1939-10-05
BE433020A (en(2012))
FR50259E (fr) 1940-01-29

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