GB585907A - Improvements in or relating to methods and apparatus for reducing the effect of interference in the observation of recurrent oscillatory signals - Google Patents

Improvements in or relating to methods and apparatus for reducing the effect of interference in the observation of recurrent oscillatory signals

Info

Publication number
GB585907A
GB585907A GB3124139A GB3124139A GB585907A GB 585907 A GB585907 A GB 585907A GB 3124139 A GB3124139 A GB 3124139A GB 3124139 A GB3124139 A GB 3124139A GB 585907 A GB585907 A GB 585907A
Authority
GB
United Kingdom
Prior art keywords
frequency
signals
interference
effect
aeroplane
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
GB3124139A
Original Assignee
Alan Dower Blumlein
Eric Lawrence Casling White
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 Alan Dower Blumlein, Eric Lawrence Casling White filed Critical Alan Dower Blumlein
Priority to GB3124139A priority Critical patent/GB585907A/en
Publication of GB585907A publication Critical patent/GB585907A/en
Application status is Expired legal-status Critical

Links

Classifications

    • GPHYSICS
    • G01MEASURING; TESTING
    • G01SRADIO 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
    • G01S7/00Details of systems according to groups G01S13/00, G01S15/00, G01S17/00
    • G01S7/02Details of systems according to groups G01S13/00, G01S15/00, G01S17/00 of systems according to group G01S13/00
    • G01S7/28Details of pulse systems
    • G01S7/285Receivers
    • G01S7/292Extracting wanted echo-signals
    • G01S7/2923Extracting wanted echo-signals based on data belonging to a number of consecutive radar periods

Abstract

585,907. Wireless signalling. BLUMLEIN, A. D., and WHITE, E. L. C. Dec. 1; 1939, No. 31241. [Class 40 (v)] A train of signals having a repeated wave form is freed from random interference which may extend over a wider frequency-band than the desired signal by a process which comprises feeding the desired signals during spaced timeintervals coinciding with the same portion of the signal train or envelope and integrating these elements over a period of time sufficient to ensure a favourable ratio of signal to interference. The invention may be applied to the detection of an aeroplane by analysing the reflected waves from short "bursts" of transmitted energy as described in Specification 581,920. The transmitted signals may be slowly varied over a predetermined range either of phase or frequency in order to minimise the effect of interference of constant frequency. Or a frequency change may be applied to' the received signals in order to balance or offset the apparent change of frequency in the reflected waves due to the Doppler effect. As shown, the transmitter 1 radiates pulses of short-wave signals under the control of a master pulse-generator 6 and a carrier source 11. Signals reflected back from the aeroplane are picked up by an aerial 2 and are fed to a superhet receiver of which the stage 4a is normally blocked until impulsed, as described in Specification 585,906. The unblocking impulse is applied from a multivibrator 5 controlled from the master pulsegenerator 6 through an adjustable phasing- device 7. The output from the pulsed. stages is heterodyned in one or more stages to a frequency of 20 kilocycles in one or more mixers 8 and then passed to a circuit 9 having a band width of Œ200 cycles. As shown the local oscillation is supplied from a mixer 10 fed from the carrier source 11 and from a stable oscillator 12 generating the desired intermediate frequency. The circuit 9 in effect integrates the successive bursts or pulses, after reflection from the aeroplane the amplitude of the built-up oscillations being proportional to the number of oscillations received, though any interference present is attenuated. Means are provided for offsetting any D÷ppler effect on the frequency due to the approach or recession of the aeroplane ; and also for preventing effects due to frequency " drift " in the oscillator stages.
GB3124139A 1939-12-01 1939-12-01 Improvements in or relating to methods and apparatus for reducing the effect of interference in the observation of recurrent oscillatory signals Expired GB585907A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
GB3124139A GB585907A (en) 1939-12-01 1939-12-01 Improvements in or relating to methods and apparatus for reducing the effect of interference in the observation of recurrent oscillatory signals

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB3124139A GB585907A (en) 1939-12-01 1939-12-01 Improvements in or relating to methods and apparatus for reducing the effect of interference in the observation of recurrent oscillatory signals

Publications (1)

Publication Number Publication Date
GB585907A true GB585907A (en) 1947-02-28

Family

ID=10320161

Family Applications (1)

Application Number Title Priority Date Filing Date
GB3124139A Expired GB585907A (en) 1939-12-01 1939-12-01 Improvements in or relating to methods and apparatus for reducing the effect of interference in the observation of recurrent oscillatory signals

Country Status (1)

Country Link
GB (1) GB585907A (en)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE977602C (en) * 1955-02-04 1967-07-20 Siemens Ag Impulsradargeraet for interference-free signal transmission for the presence of moving targets
DE977893C (en) * 1955-02-04 1972-04-06 Siemens Ag Impulsradargeraet for interference-free signal transmission for the presence of moving targets
US7116963B2 (en) 1996-09-13 2006-10-03 University Of Washington Simplified high frequency tuner and tuning method

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE977602C (en) * 1955-02-04 1967-07-20 Siemens Ag Impulsradargeraet for interference-free signal transmission for the presence of moving targets
DE977893C (en) * 1955-02-04 1972-04-06 Siemens Ag Impulsradargeraet for interference-free signal transmission for the presence of moving targets
US7116963B2 (en) 1996-09-13 2006-10-03 University Of Washington Simplified high frequency tuner and tuning method
US8005450B2 (en) * 1996-09-13 2011-08-23 University Of Washington Simplified high frequency tuner and tuning method

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