GB557563A - Improvements in or relating to ultra high frequency radio signalling systems - Google Patents

Improvements in or relating to ultra high frequency radio signalling systems

Info

Publication number
GB557563A
GB557563A GB703542A GB703542A GB557563A GB 557563 A GB557563 A GB 557563A GB 703542 A GB703542 A GB 703542A GB 703542 A GB703542 A GB 703542A GB 557563 A GB557563 A GB 557563A
Authority
GB
United Kingdom
Prior art keywords
frequency
mean
wave
modulation
carrier
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
Application number
GB703542A
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.)
STC PLC
Original Assignee
Standard Telephone and Cables PLC
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 Standard Telephone and Cables PLC filed Critical Standard Telephone and Cables PLC
Priority to GB703542A priority Critical patent/GB557563A/en
Publication of GB557563A publication Critical patent/GB557563A/en
Expired legal-status Critical Current

Links

Classifications

    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
    • G01S1/00—Beacons or beacon systems transmitting signals having a characteristic or characteristics capable of being detected by non-directional receivers and defining directions, positions, or position lines fixed relatively to the beacon transmitters; Receivers co-operating therewith
    • G01S1/02—Beacons or beacon systems transmitting signals having a characteristic or characteristics capable of being detected by non-directional receivers and defining directions, positions, or position lines fixed relatively to the beacon transmitters; Receivers co-operating therewith using radio waves

Landscapes

  • Engineering & Computer Science (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Radar, Positioning & Navigation (AREA)
  • Remote Sensing (AREA)
  • Transducers For Ultrasonic Waves (AREA)

Abstract

557,563. Wireless signalling. STANDARD TELEPHONES & CABLES, Ltd., EARP, C. W., and STRONG, C. E. May 22, 1942, No. 7035. [Class 40 (v)] In an ultra-high frequency radio system in which signals are conveyed by keying interruption or amplitude modulation, the carrier wave is frequency-modulated about a mean frequency and at the receiver is heterodyned with a constant frequency substantially equal to the mean carrier frequency. The frequency modulation is a periodic frequency sweep as indicated .in Fig. 2a, the repetition frequency being higher than the highest signal frequency. At the receiver, Fig. 1, the incoming wave is heterodyned by a wave of about the mean incoming frequency and the difference frequency is passed by resistancecapacity couplings through the I.F. stages V<SP>3</SP>, V<SP>4</SP> to a second detector D2. The couplings are such that low frequencies up to about 10 kc. and frequencies above 1 mc. are suppressed, with the result that energy reaches the second detector D2 in the form of pulses at the repetition frequency as indicated in Fig. 2. The width of the pulses is determined by the relative values of the frequency sweep at the transmitter and the band width of the receiver I.F. stages. The pulses may be passed through a valve V<SP>5</SP> with an output circuit tuned to the pulse frequency, to an output transformer T. The heterodyne may be provided by a crystal oscillator V<SP>1</SP> with its plate circuit tuned to a harmonic of the crystal frequency and feeding a harmonic generator V<SP>2</SP> giving a further multiplication of frequency in the circuit C<SP>1</SP>, L<SP>1</SP>. A resonant concentric line CTL is tuned by a condenser C<SP>2</SP> to the mean carrier frequency, and the incoming carrier and the oscillation in C<SP>1</SP>, L<SP>1</SP> are both applied to the line and to a diode D<SP>1</SP>, the beat oscillation being developed across the resistance R<SP>1</SP>. The wave form of the frequency modulation may be sinusoidal or sawtooth, and the modulation may be effected as described in Specification 556,208.
GB703542A 1942-05-22 1942-05-22 Improvements in or relating to ultra high frequency radio signalling systems Expired GB557563A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
GB703542A GB557563A (en) 1942-05-22 1942-05-22 Improvements in or relating to ultra high frequency radio signalling systems

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB703542A GB557563A (en) 1942-05-22 1942-05-22 Improvements in or relating to ultra high frequency radio signalling systems

Publications (1)

Publication Number Publication Date
GB557563A true GB557563A (en) 1943-11-25

Family

ID=9825394

Family Applications (1)

Application Number Title Priority Date Filing Date
GB703542A Expired GB557563A (en) 1942-05-22 1942-05-22 Improvements in or relating to ultra high frequency radio signalling systems

Country Status (1)

Country Link
GB (1) GB557563A (en)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2477547A (en) * 1945-01-03 1949-07-26 Bendix Aviat Corp Modulation of radio-frequency oscillations
US2539797A (en) * 1946-05-09 1951-01-30 Rca Corp Signal transmission system
US2649539A (en) * 1948-02-21 1953-08-18 Bell Telephone Labor Inc Microwave carrier telephone system
US2994765A (en) * 1957-08-09 1961-08-01 Eugene C Adam Emergency vehicle alarm device

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2477547A (en) * 1945-01-03 1949-07-26 Bendix Aviat Corp Modulation of radio-frequency oscillations
US2539797A (en) * 1946-05-09 1951-01-30 Rca Corp Signal transmission system
US2649539A (en) * 1948-02-21 1953-08-18 Bell Telephone Labor Inc Microwave carrier telephone system
US2994765A (en) * 1957-08-09 1961-08-01 Eugene C Adam Emergency vehicle alarm device

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