GB1433140A - Indentity transponders - Google Patents

Indentity transponders

Info

Publication number
GB1433140A
GB1433140A GB4782372A GB4782372A GB1433140A GB 1433140 A GB1433140 A GB 1433140A GB 4782372 A GB4782372 A GB 4782372A GB 4782372 A GB4782372 A GB 4782372A GB 1433140 A GB1433140 A GB 1433140A
Authority
GB
United Kingdom
Prior art keywords
delay line
transducer
dipoles
transducers
supplied
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
GB4782372A
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.)
National Research Development Corp UK
Original Assignee
National Research Development Corp UK
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 National Research Development Corp UK filed Critical National Research Development Corp UK
Priority to GB4782372A priority Critical patent/GB1433140A/en
Publication of GB1433140A publication Critical patent/GB1433140A/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
    • G01S13/74—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
    • G01S13/751—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 wherein the responder or reflector radiates a coded signal
    • G01S13/755—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 wherein the responder or reflector radiates a coded signal using delay lines, e.g. acoustic delay lines

Abstract

1433140 Transponder apparatus NATIONAL RESEARCH DEVELOPMENT CORP 4 Sept 1973 [17 Oct 1972] 47823/72 Heading H4L A transponder for use as a coded identity label receives an interrogation pulse via aerial 10 which is supplied to an acoustic delay line 14 via a transducer 16. Delay line 14 is tapped at five points by transducers 18 to 22 connected to respective transmitting dipoles 24 which are screened from each other, the dipoles confronting an electrically conductive coding screen having apertures 30, 31, 32 corresponding to selected dipoles. A receiver at the interrogation station will receive three pulses spaced in time in accordance with the spacing of the apertures on the coding screen and preceded by clutter due to direct reflection which is distinguishable from the coded pulses. In an alternative arrangement the coding screen is dispensed with and selected transducers are connected in reversed manner to their corresponding dipole to provide a 180 degree phase shift. Other phase shifts may be obtained by altering the position of the transducer concerned on the delay line by a fraction of the wavelength of the acoustic waves. In a modification, Fig. 3 (not shown), the aerial 10 is replaced by two aerials each arranged to receive a respective one of two transmitted frequencies which are supplied to a mixer to provide for example, the difference frequency. This difference frequency is supplied to the transducer 16 as before the resulting response signal being free to clutter. In a further arrangement, Figs. 4 and 5 (not shown), a plurality of dipoles are connected via transducers to tappings on an acoustic delay line and co-operate with an apertured coding plate as before. Each dipole is connected to a diode mixer and is interrogated by two frequencies, the difference frequency being applied via the respective transducers to the delay line. The resulting output pulse sequence is supplied via a transducer as a response signal to a loop aerial tuned to the difference frequency.
GB4782372A 1972-10-17 1972-10-17 Indentity transponders Expired GB1433140A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
GB4782372A GB1433140A (en) 1972-10-17 1972-10-17 Indentity transponders

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB4782372A GB1433140A (en) 1972-10-17 1972-10-17 Indentity transponders

Publications (1)

Publication Number Publication Date
GB1433140A true GB1433140A (en) 1976-04-22

Family

ID=10446368

Family Applications (1)

Application Number Title Priority Date Filing Date
GB4782372A Expired GB1433140A (en) 1972-10-17 1972-10-17 Indentity transponders

Country Status (1)

Country Link
GB (1) GB1433140A (en)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2515362A1 (en) * 1981-10-23 1983-04-29 Knogo Corp METHOD AND APPARATUS FOR DETECTING THE FLIGHT BY DETECTING THE ATTENUATION OF A RESONANT CIRCUIT
WO1994003982A1 (en) * 1992-07-31 1994-02-17 Micro Design As Identification device
GB2352936A (en) * 1999-05-22 2001-02-07 Marconi Caswell Ltd Identification tag with acoustic modulation of radio signal

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2515362A1 (en) * 1981-10-23 1983-04-29 Knogo Corp METHOD AND APPARATUS FOR DETECTING THE FLIGHT BY DETECTING THE ATTENUATION OF A RESONANT CIRCUIT
WO1994003982A1 (en) * 1992-07-31 1994-02-17 Micro Design As Identification device
AU681347B2 (en) * 1992-07-31 1997-08-28 Q-Free Asa Identification device
GB2352936A (en) * 1999-05-22 2001-02-07 Marconi Caswell Ltd Identification tag with acoustic modulation of radio signal
GB2352936B (en) * 1999-05-22 2001-11-21 Marconi Caswell Ltd Identification tag
US6744367B1 (en) 1999-05-22 2004-06-01 Marconi Data Systems Limited Identification tag

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Legal Events

Date Code Title Description
PS Patent sealed
PLNP Patent lapsed through nonpayment of renewal fees