EP0186483A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Transponder systems
Assignee: SENELCO Ltd
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Filing: 1985-12-20
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Granted: —
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Expires: 2005-12-20
Abstract
Abstract In a transponder system where a central interrogator transmits an electromagnetic field over an area in which transponders carried by moving objects are to be detected, the interrogator includes two coplanar antennae one arranged as a loop and the other in a figure of eight configuration, in order to generate fields at right angles to one another so that transponders can be detected regardless of their orientation. A phase shift may be introduced between the fields in order to generate a circulatory polarized field.
Inventors
- 👤 Stephen Philip Curtis
- 👤 Gary Victor Jordan
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-03 15:48
CPC Classifications
G; G06; G06K; G06K7/00; G06K7/10; G06K7/10009; G06K7/10316; G06K7/10346; G01; G01S; G01S13/00; G01S13/74; G01S13/76; G01S13/762; G01S7/00; G01S7/02; G01S7/024; G01S7/026; G08; G08B; G08B13/00; G08B13/22; G08B13/24; G08B13/2402; G08B13/2465; G08B13/2468; G08B13/2471; G08B13/2474; G08B13/2477; H; H01; H01Q; H01Q21/00; H01Q21/24; H01Q7/00
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
66 words
A transponder system comprising a transponder to be attached to an object to be identified and an interrogator for interrogating the transponder, the interrogator including an antenna system comprising first and second antennae configured so as to be generally coplanar and providing signals which are in a direction generally at right angles to one another in a region in which interrogation of the transponder is required.
Claim 2
Dependent Claim
66 words
A transponder system comprising a transponder to be attached to an object to be identified and an interrogator for interrogating the transponder, the interrogator including an antenna system comprising first and second antennae configured so as to be generally coplanar and providing signals which are in a direction generally at right angles to one another in a region in which interrogation of the transponder is required.
Claim 3
Dependent Claim
59 words
A transponder system as claimed in claim 1 wherein the first and second antennae are arranged to be powered simultaneously and a phase shift is introduced between the two signals supplied to the antennae so as to provide a field which provides a component at all field positions for activating the transponder regardless of the orientation of the transponder.
Claim 4
Dependent Claim
25 words
A transponder system as claimed in claim 1 wherein the first antenna comprises a loop and the second antenna comprises a figure of eight configuration.
References Cited (Backward Citations)
No citation records indexed.
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