GB645181A - Improvements in or relating to radar systems - Google Patents

Improvements in or relating to radar systems

Info

Publication number
GB645181A
GB645181A GB5092/46A GB509246A GB645181A GB 645181 A GB645181 A GB 645181A GB 5092/46 A GB5092/46 A GB 5092/46A GB 509246 A GB509246 A GB 509246A GB 645181 A GB645181 A GB 645181A
Authority
GB
United Kingdom
Prior art keywords
signal
received
frequency
filter
signals
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
GB5092/46A
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.)
Marconis Wireless Telegraph Co Ltd
BAE Systems Electronics Ltd
Original Assignee
Marconis Wireless Telegraph Co Ltd
Marconi 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 Marconis Wireless Telegraph Co Ltd, Marconi Co Ltd filed Critical Marconis Wireless Telegraph Co Ltd
Publication of GB645181A publication Critical patent/GB645181A/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
    • G01S13/00—Systems using the reflection or reradiation of radio waves, e.g. radar systems; Analogous systems using reflection or reradiation of waves whose nature or wavelength is irrelevant or unspecified
    • G01S13/02—Systems using reflection of radio waves, e.g. primary radar systems; Analogous systems
    • G01S13/50—Systems of measurement based on relative movement of target
    • G01S13/52—Discriminating between fixed and moving objects or between objects moving at different speeds
    • G01S13/522—Discriminating between fixed and moving objects or between objects moving at different speeds using transmissions of interrupted pulse modulated waves
    • G01S13/524—Discriminating between fixed and moving objects or between objects moving at different speeds using transmissions of interrupted pulse modulated waves based upon the phase or frequency shift resulting from movement of objects, with reference to the transmitted signals, e.g. coherent MTi
    • G01S13/53—Discriminating between fixed and moving objects or between objects moving at different speeds using transmissions of interrupted pulse modulated waves based upon the phase or frequency shift resulting from movement of objects, with reference to the transmitted signals, e.g. coherent MTi performing filtering on a single spectral line and associated with one or more range gates with a phase detector or a frequency mixer to extract the Doppler information, e.g. pulse Doppler radar
    • 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
    • G01S13/00—Systems using the reflection or reradiation of radio waves, e.g. radar systems; Analogous systems using reflection or reradiation of waves whose nature or wavelength is irrelevant or unspecified
    • G01S13/02—Systems using reflection of radio waves, e.g. primary radar systems; Analogous systems

Landscapes

  • Engineering & Computer Science (AREA)
  • Radar, Positioning & Navigation (AREA)
  • Remote Sensing (AREA)
  • Physics & Mathematics (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • General Physics & Mathematics (AREA)
  • Spectroscopy & Molecular Physics (AREA)
  • Radar Systems Or Details Thereof (AREA)

Abstract

645,181. Radiolocation. MARCONI'S WIRELESS TELEGRAPH CO., Ltd. Feb. 18, 1946, No. 5092. Convention date, Sept. 28, 1944. Drawings to Specification. [Class 40 (vii)] In order to increase the signal-to-noise ratio, whenever it is less than unity, of the received signals in a pulse-radar system, a large-amplitude signal of the carrier frequency (radio or intermediate frequency) is added to the received signal before demodulation. In one embodiment one sideband of the received echo signals is removed in the I.F. stages of the receiver. The output from the side-band filter is mixed with a signal of the transmission frequency which is applied through a filter from the radar transmitter. The combined signal is applied to the second detector, the output of which is amplified and displayed on a cathode-ray tube indicator having a circular sweep. In a second embodiment, the locally-produced, large-amplitude, signal is obtained from the I.F. circuits of the receiver, so that the occurrence of a difference in frequency between the received and locally-produced signals, due to the Doppler effect, is prevented. The intermediate frequency signal is passed through a narrowband filter to remove noise modulation, amplified and then mixed with the single-sideband signal as before. The narrow-band filter is preferably tunable as the intermediate frequency varies due to the Doppler effect. In a third embodiment employing both sidebands of the received signal, means are provided to maintain the added signal in phase with the carrier of the received signal. The locallyproduced signal is derived from the transmitter and an adjustable phase-shifting circuit is inserted in between the carrier-frequency filter and the mixer wherein the two signals are combined.
GB5092/46A 1944-09-28 1946-02-18 Improvements in or relating to radar systems Expired GB645181A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US645181XA 1944-09-28 1944-09-28

Publications (1)

Publication Number Publication Date
GB645181A true GB645181A (en) 1950-10-25

Family

ID=22056521

Family Applications (1)

Application Number Title Priority Date Filing Date
GB5092/46A Expired GB645181A (en) 1944-09-28 1946-02-18 Improvements in or relating to radar systems

Country Status (1)

Country Link
GB (1) GB645181A (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5998528A (en) * 1995-06-07 1999-12-07 Amcol International Corporation Viscous carrier compositions, including gels, formed with an organic liquid carrier, a layered material: polymer complex, and a di-, and/or tri-valent cation
US6057396A (en) * 1996-12-06 2000-05-02 Amcol International Corporation Intercalates formed by co-intercalation of monomer, oligomer or polymer intercalants and surface modifier intercalants and layered materials and nonocomposites prepared with the intercalates

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5998528A (en) * 1995-06-07 1999-12-07 Amcol International Corporation Viscous carrier compositions, including gels, formed with an organic liquid carrier, a layered material: polymer complex, and a di-, and/or tri-valent cation
US6057396A (en) * 1996-12-06 2000-05-02 Amcol International Corporation Intercalates formed by co-intercalation of monomer, oligomer or polymer intercalants and surface modifier intercalants and layered materials and nonocomposites prepared with the intercalates

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