GB667037A - Improvements in apparatus for detecting a selected object from a group of objects - Google Patents

Improvements in apparatus for detecting a selected object from a group of objects

Info

Publication number
GB667037A
GB667037A GB17747/49A GB1774749A GB667037A GB 667037 A GB667037 A GB 667037A GB 17747/49 A GB17747/49 A GB 17747/49A GB 1774749 A GB1774749 A GB 1774749A GB 667037 A GB667037 A GB 667037A
Authority
GB
United Kingdom
Prior art keywords
polarization
train
modifying
waves
group
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
GB17747/49A
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.)
STIN
Original Assignee
STIN
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 STIN filed Critical STIN
Publication of GB667037A publication Critical patent/GB667037A/en
Expired legal-status Critical Current

Links

Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01Q—ANTENNAS, i.e. RADIO AERIALS
    • H01Q25/00—Antennas or antenna systems providing at least two radiating patterns
    • H01Q25/001—Crossed polarisation dual antennas
    • 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
    • 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
    • G01S13/74—Systems using reradiation of radio waves, e.g. secondary radar systems; Analogous systems
    • G01S13/75—Systems using reradiation of radio waves, e.g. secondary radar systems; Analogous systems using transponders powered from received waves, e.g. using passive transponders, or using passive reflectors
    • 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
    • G01S7/00—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00
    • G01S7/02—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00 of systems according to group G01S13/00
    • G01S7/024—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00 of systems according to group G01S13/00 using polarisation effects
    • G01S7/025—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00 of systems according to group G01S13/00 using polarisation effects involving the transmission of linearly polarised waves
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01Q—ANTENNAS, i.e. RADIO AERIALS
    • H01Q15/00—Devices for reflection, refraction, diffraction or polarisation of waves radiated from an antenna, e.g. quasi-optical devices
    • H01Q15/14—Reflecting surfaces; Equivalent structures
    • H01Q15/22—Reflecting surfaces; Equivalent structures functioning also as polarisation filter
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01Q—ANTENNAS, i.e. RADIO AERIALS
    • H01Q15/00—Devices for reflection, refraction, diffraction or polarisation of waves radiated from an antenna, e.g. quasi-optical devices
    • H01Q15/24—Polarising devices; Polarisation filters 
    • H01Q15/242—Polarisation converters

Landscapes

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

Abstract

667,037. Railway signals &c. SOC. TECHNIQUE POUR L'INDUSTRIE NOUVELLE SOC. ANON. STIN. July 5, 1949. [July 6, 1948; March 30, 1949] Nos. 17747/49 and 17748/49. Drawings to Specification. Class 105. [Also in Group XL (c)] The invention comprises apparatus for detecting the presence of a particular object consisting of means for transmitting radio-frequency electromagnetic waves having a pre-determined direction of polarization and means carried by the object for modifying the direction of polarization of the incident waves to render the energy thereof receivable by the antenna of receiving means capable of receiving the modified waves only. To determine when the last vehicle of a train has passed a given point along the track the transmitter and receiver may be set up at the given point and the last vehicle of the train carry a reflector capable of modifying the polarization of the incident waves. In another application the modifying device is placed beside the track as a "signal" and may receive radiation from a transmitter situated some distance away at a control point. The receiver in this case is carried by the train and it is arranged that modified signals can only be received close to the device. For the construction of suitable aerials and polarization changing devices (see Group XL (c)).
GB17747/49A 1948-07-06 1949-07-05 Improvements in apparatus for detecting a selected object from a group of objects Expired GB667037A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CH667037X 1948-07-06

Publications (1)

Publication Number Publication Date
GB667037A true GB667037A (en) 1952-02-20

Family

ID=4527362

Family Applications (1)

Application Number Title Priority Date Filing Date
GB17747/49A Expired GB667037A (en) 1948-07-06 1949-07-05 Improvements in apparatus for detecting a selected object from a group of objects

Country Status (4)

Country Link
BE (1) BE489994A (en)
CH (1) CH276751A (en)
FR (1) FR990098A (en)
GB (1) GB667037A (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN113242981A (en) * 2018-08-07 2021-08-10 七哈格斯实验室公司 Polarization axis attenuation and cross-polarization resistant antenna orientation assembly for tracked objects

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE977757C (en) * 1962-02-09 1969-11-06 Telefunken Patent Electronic proximity switch
FR2131832B1 (en) * 1971-03-29 1974-05-31 Automatisme Cie Gle
FR2233668A1 (en) * 1973-06-14 1975-01-10 Radiotechnique Compelec Electromagnetic microwave surveillance barrier - frontal dimensions are small and receiver element structure is simplified

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN113242981A (en) * 2018-08-07 2021-08-10 七哈格斯实验室公司 Polarization axis attenuation and cross-polarization resistant antenna orientation assembly for tracked objects

Also Published As

Publication number Publication date
CH276751A (en) 1951-07-31
BE489994A (en)
FR990098A (en) 1951-09-17

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