Tunable RFID tag for global applications

• US 20060220869A1
• Filed: 03/15/2005
• Published: 10/05/2006
• Est. Priority Date: 03/15/2005
• Status: Active Grant

• Current Assignee: Intermec IP Corporation (Honeywell International Inc.)
• Original Assignee: Intermec IP Corporation (Honeywell International Inc.)
• Inventors: Lam, For Sander, Nikitin, Pavel, Kodukula, Venkata S.
• Granted Patent: US 7,323,977 B2
• Time in Patent Office: Days
• US Class Current: 340/572.700
• CPC Class Codes: G06K 19/0724 the arrangement being a circuit for communicating at a plurality of frequencies, e.g. for managing time multiplexed communication over at least two antennas of different types
• 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 19/07749 the record carrier being capable of non-contact communication, e.g. constructional details of the antenna of a non-contact smart card
• CPC Class Codes: G06K 19/07786 the antenna being of the HF type, such as a dipole

Abstract

An RF transponder comprises a transponder integrated circuit, an antenna connected to the transponder integrated circuit, and at least one parasitic element adapted to interact electrically with the antenna and thereby affect antenna impedance. The orientation of the parasitic element with respect to the antenna is selected to achieve a desired operational frequency band for the RF transponder. Specifically, the spacing between the antenna and the parasitic element is selected to achieve the desired operational frequency band. For example, a first selected spacing may enable an operational frequency band suitable for a first geographic region (e.g., the United States), a second selected spacing may enable an operational frequency band suitable for a second geographic region (e.g., Europe), and a third selected spacing may enable an operational frequency band suitable for a third geographic region (e.g., Japan).

Claims

1. An RF transponder, comprising:

a transponder integrated circuit;

an antenna connected to said RF transponder integrated circuit; and

at least one parasitic element adapted to interact electrically with said antenna and thereby affect antenna impedance, wherein orientation of said at least one parasitic element with respect to said antenna is selected to achieve a desired operational frequency band for the RF transponder.

2. The RF transponder of claim 1, wherein said antenna comprises a dipole antenna.

3. The RF-transponder of claim 1, wherein said antenna comprises a folded dipole antenna.

4. The RF transponder of claim 1, wherein said antenna comprises a meander dipole antenna.

5. The RF transponder of claim 1, wherein spacing between said antenna and said at least one parasitic element is selected to achieve said desired operational frequency band.

6. The RF transponder of claim 5, wherein a first selected spacing enables an operational frequency band suitable for a first geographic region, a second selected spacing enables an operational frequency band suitable for a second geographic region, and a third selected spacing enables an operational frequency band suitable for a third geographic region.

7. The RF transponder of claim 1, wherein spacing between said antenna and said at least one parasitic element is selected to achieve said desired operational frequency band for a particular geographic region.

8. The RF transponder of claim 1, wherein spacing between said antenna and said at least one parasitic element is selected to achieve said desired operational frequency band for a particular material to which the RF transponder is affixed.

9. The RF transponder of claim 1, wherein at least one said parasitic elements further comprises an L-shaped structure.

10. The RF transponder of claim 1, further comprising a substrate layer, said transponder integrated circuit and said antenna being affixed to said substrate layer.

11. The RF transponder of claim 10, wherein said substrate layer further comprises indicia provided thereon defining plural predetermined locations for affixing said at least one parasitic elements thereto.

12. The RF transponder of claim 11, wherein said at least one parasitic elements further comprise an adhesive layer permitting attachment to at least one of said plural predetermined locations.

13. The RF transponder of claim 10, further comprising an insert card having said at least one parasitic elements formed thereon, said insert card being placed in close proximity to said substrate layer.

14. The RF transponder of claim 13, wherein said insert card is adhesively coupled to said substrate layer.

15. The RF transponder of claim 13, wherein said at least one parasitic elements are comprised of conductive ink.

16. A method of tuning an RF transponder having a transponder integrated circuit and an antenna connected to said RF transponder integrated circuit, the method comprising orienting at least one parasitic element with respect to said antenna to achieve a desired operational frequency band for the RF transponder, said at least one parasitic element being adapted to interact electrically with said antenna and thereby affect antenna impedance in correspondence with spacing between said antenna and said at least one parasitic element.

17. The method of claim 16, wherein said orienting step further comprises selecting said spacing between said antenna and said at least one parasitic element to achieve said desired operational frequency band.

18. The method of claim 17, further comprising selecting a first spacing to enable an operational frequency band suitable for a first geographic region, selecting a second spacing to enable an operational frequency band suitable for a second geographic region, and selecting a third spacing to enable an operational frequency band suitable for a third geographic region.

19. The method of claim 17, further comprising selecting said spacing to enable an operational frequency band suitable for a particular geographic region.

20. The method of claim 17, further comprising selecting said spacing to enable an operational frequency band suitable for a particular material to which the RF transponder is affixed

21. The method of claim 17, wherein said RF transponder further comprises a substrate layer, said orienting step further comprising affixing said at least one parasitic element to said substrate layer.

22. The method of claim 21, wherein said substrate layer further comprises indicia provided thereon defining plural predetermined locations, said orienting step further comprising selecting one of said plural predetermined locations for affixing said at least one parasitic element thereto.

23. The method of claim 22, wherein said affixing step further comprises adhesively affixing said at least one parasitic element to at least one of said plural predetermined locations.

24. The method of claim 17, further comprising providing said at least one parasitic element on an insert card and placing said insert card in close proximity to said RF transponder.

25. The method of claim 24, further comprising adhesively coupling said insert card to said substrate layer.

26. The method of claim 24, further comprising printing said at least one parasitic elements on said insert card using conductive ink.

27. An RF transponder kit, comprising:

at least one RF transponder including a substrate, a transponder integrated circuit affixed to said substrate, and an antenna affixed to said substrate and electrically connected to said transponder integrated circuit; and

a plurality of parasitic elements each adapted to interact electrically with said antenna and thereby affect antenna impedance, wherein selected ones of said plural parasitic elements are oriented with respect to said antenna to achieve a desired operational frequency band for the RF transponder.

28. The RF transponder kit of claim 27, wherein said antenna comprises a dipole antenna.

29. The RF transponder kit of claim 27, wherein said antenna comprises a folded dipole antenna.

30. The RF transponder kit of claim 27, wherein said antenna comprises a meander dipole antenna.

31. The RF transponder kit of claim 27, wherein spacing between said antenna and said selected ones of said plural parasitic element is selected to achieve said desired operational frequency band.

32. The RF transponder kit of claim 31, wherein a first selected spacing enables an operational frequency band suitable for a first geographic region, a second selected spacing enables an operational frequency band suitable for a second geographic region, and a third selected spacing enables an operational frequency band suitable for a third geographic region.

33. The RF transponder of claim 31, wherein spacing between said antenna and said at least one parasitic element is selected to achieve said desired operational frequency band for a particular material to which the RF transponder is affixed.

34. The RF transponder kit of claim 27, wherein at least one of said plural parasitic elements further comprises an L-shaped structure.

35. The RF transponder kit of claim 27, wherein said substrate layer further comprises indicia provided thereon defining plural predetermined locations for affixing said selected ones of said plural parasitic elements thereto.

36. The RF transponder kit of claim 35, wherein said plural parasitic elements each further comprises an adhesive layer permitting attachment to said plural predetermined locations.

37. The RF transponder kit of claim 27, further comprising an insert card having ones of said plural parasitic elements formed thereon, said insert card being adapted for placement in close proximity to said substrate layer.

38. The RF transponder kit of claim 37, wherein said ones of said plural parasitic elements are comprised of conductive ink.