Electronic label interrogation through incidental electromagnetic radiation

• US 20040201456A1
• Filed: 04/27/2004
• Published: 10/14/2004
• Est. Priority Date: 10/29/2001
• Status: Active Grant

• Current Assignee: Tagsys SA
• Original Assignee: Tagsys Australia Pty Limited
• Inventors: Cole, Peter Harold
• Granted Patent: US 7,221,259 B2
• Time in Patent Office: Days
• US Class Current: 340/10.3
• CPC Class Codes: G06K 19/0701 at least one of the integrated circuit chips comprising an arrangement for power management
• CPC Class Codes: G06K 19/0723 the record carrier comprising an arrangement for non-contact communication, e.g. wireless communication circuits on transponder cards, non-contact smart cards or RFIDs
• CPC Class Codes: G06K 19/0726 the arrangement including a circuit for tuning the resonance frequency of an antenna on the record carrier
• CPC Class Codes: G06K 7/0008 General problems related to the reading of electronic memory record carriers, independent of its reading method, e.g. power transfer
• CPC Class Codes: G08B 13/2414 using inductive tags
• CPC Class Codes: G08B 13/2417 having a radio frequency identification chip
• CPC Class Codes: G08B 13/2488 Timing issues, e.g. synchronising measures to avoid signal collision, with multiple emitters or a single emitter and receiver
• CPC Class Codes: G08B 29/185 Signal analysis techniques for reducing or preventing false alarms or for enhancing the reliability of the system

Abstract

A system for electromagnetically interrogating electronically coded labels is provided. The system includes at least one electromagnetically interrogatable electronic coded label, an interrogator containing a generator of electromagnetic interrogation signals and a receiver of electromagnetic reply signals from the label. The system is adapted to make use of electromagnetic signals, other than those generated by the interrogator, which may reach the label.

Claims

1. A system for electromagnetically interrogating electronically coded labels including:

at least one electromagnetically interrogatable electronic coded label; and

an interrogator containing a generator of electromagnetic interrogation signals and a receiver of electromagnetic reply signals from said label;

wherein said system is adapted to make use of electromagnetic signals, other than those generated by said interrogator, which reach said label.

2. A system as claimed in claim 1 wherein said interrogator has access to information about electromagnetic signals, other than those generated by said interrogator, which reach said label.

3. A system as claimed in claim 2 wherein said interrogator varies frequency of an interrogation signal in response to said information.

4. A system as claimed in claim 2 wherein said interrogator varies phase of an interrogation signal in response to said information.

5. A system as claimed in claim 2 wherein said interrogator generates frequency hopping signals and selects a hopping pattern in response to said information.

6. A system as claimed in any one of the preceding claims wherein said interrogation signals combine with said other signals to create a spatial interference pattern.

7. A system as claimed in claim 6 wherein said interrogation signals are varied in time so that said spatial interference pattern between said interrogation signals and said other signals which reach said label varies in time.

8. A system as claimed in claim 6 or 7 wherein said interference pattern enhances excitation of said label.

9. A system as claimed in any one of the preceding claims wherein said interrogation signals use the same frequency as said other signals which reach said label.

10. A system as claimed in any one of claims 1 to 8 wherein said interrogation signals use a frequency different from said other signals which reach said label.

11. A system as claimed in any one of the preceding claims wherein said interrogation signals are adapted to ensure label replies are at frequencies different from said other signals which reach said receiver of said interrogator.

12. A system as claimed in claim 1 wherein said system and a further communication system are adapted to occupy different channels of a regulated band, and said system is adapted to generate sidebands at frequencies distinct from sidebands generated by mixing within said label, carrier signals of said further communication system and said system.

13. A system as claimed in any one of the preceding claims wherein said interrogation signals are modulated to transmit information to said label.

14. A system as claimed in any one of the preceding claims wherein interaction between said interrogation signals and said other signals which reach said label provides timing information within said label.

15. A system as claimed in any one of claims 1 to 5 wherein an interference pattern of said interrogation signals and said other signals which reach said label provides command or data to said label.

16. A system as claimed in any one of the preceding claims wherein said label operates with said interrogation signals alone or with said other signals reaching said label.

17. A system as claimed in any one of the preceding claims wherein said interrogator includes an antenna system in which some elements contribute to generation of an electromagnetic field at a position of electromagnetic compatibility testing, and a different set of elements generate an electromagnetic field in a region wherein said coded labels are located.

18. A system as claimed in claim 1 wherein said labels receive sufficient operating power for their operation from a modulated signal of a further communication system, said labels further modulating and backscattering the signal that they receive, and said interrogator receives both said modulated signal of said further communication system and said modulated and backscattered signal of said system, and uses said communication signal as an aid to decoding said backscattered signal.

19. A system as claimed in claim 18 wherein said backscattered signal provided by said labels is at or below a generic signal level below which electromagnetic compatibility regulations do not apply.

20. A system as claimed in claim 1 wherein said interrogator and a data link share common transmitter antenna.

21. A system as claimed in claim 1 wherein said electromagnetic signals come from a data link that emits an un-modulated carrier when no data is being transmitted.

24. A system as claimed in claim 1 wherein said interrogator has access to information about electromagnetic signals, other than those generated by said interrogator, which reach said label.

25. A system as claimed in claim 2 wherein said interrogator varies frequency of an interrogation signal in response to said information.

26. A system as claimed in claim 2 wherein said interrogator varies phase of an interrogation signal in response to said information.

27. A system as claimed in claim 2 wherein said interrogator generates frequency hopping signals and selects a hopping pattern in response to said information.

28. A system as claimed in claim 1 wherein said interrogation signals combine with said other signals to create a spatial interference pattern.

29. A system as claimed in claim 6 wherein said interrogation signals are varied in time so that said spatial interference pattern between said interrogation signals and said other signals which reach said label varies in time.

30. A system as claimed in claim 6 wherein said interference pattern enhances excitation of said label.

31. A system as claimed in claim 1 wherein said interrogation signals use the same frequency as said other signals which reach said label.

32. A system as claimed in claim 1 wherein said interrogation signals use a frequency different from said other signals which reach said label.

33. A system as claimed in claim 1 wherein said interrogation signals are adapted to ensure label replies are at frequencies different from said other signals which reach said receiver of said interrogator.

34. A system as claimed in claim 1 wherein said system and a further communication system are adapted to occupy different channels of a regulated band, and said system is adapted to generate sidebands at frequencies distinct from sidebands generated by mixing within said label, carrier signals of said further communication system and said system.

35. A system as claimed in claim 1 wherein said interrogation signals are modulated to transmit information to said label.

36. A system as claimed in claim 1 wherein interaction between said interrogation signals and said other signals which reach said label provides timing information within said label.

37. A system as claimed in claim 1 wherein an interference pattern of said interrogation signals and said other signals which reach said label provides command or data to said label.

38. A system as claimed in claim 1 wherein said label operates with said interrogation signals alone or with said other signals reaching said label.

39. A system as claimed in claim 1 wherein said interrogator includes an antenna system in which some elements contribute to generation of an electromagnetic field at a position of electromagnetic compatibility testing, and a different set of elements generate an electromagnetic field in a region wherein said coded labels are located.

40. A system as claimed in claim 1 wherein said labels receive sufficient operating power for their operation from a modulated signal of a further communication system, said labels further modulating and backscattering the signal that they receive, and said interrogator receives both said modulated signal of said further communication system and said modulated and backscattered signal of said system, and uses said communication signal as an aid to decoding said backscattered signal.

41. A system as claimed in claim 18 wherein said backscattered signal provided by said labels is at or below a generic signal level below which electromagnetic compatibility regulations do not apply.

42. A system as claimed in claim 1 wherein said interrogator and a data link share common transmitter antenna.

43. A system as claimed in claim 1 wherein said electromagnetic signals come from a data link that emits an un-modulated carrier when no data is being transmitted.

22. A system for electromagnetically interrogating electronically coded labels substantially as herein described with reference to the accompanying drawings.

23. A system for electromagnetically interrogating electronically coded labels including:

at least one electromagnetically interrogatable electronic coded label; and

an interrogator containing a generator of electromagnetic interrogation signals and a receiver of electromagnetic reply signals from said label;

wherein said system is adapted to make use of electromagnetic signals, other than those generated by said interrogator, which reach said label.