RFID device with magnetic coupling

• US 20060044769A1
• Filed: 09/01/2004
• Published: 03/02/2006
• Est. Priority Date: 09/01/2004
• Status: Abandoned Application

• Current Assignee: Avery Dennison Corporation
• Original Assignee: Avery Dennison Corporation
• Inventors: Forster, Ian J., Weakley, Thomas Craig
• Application Number:
  US10/931,863
• Publication Number:
  US 20060044769A1
• Time in Patent Office: Days
• US Class Current: 361/760
• 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 19/07756 the connection being non-galvanic, e.g. capacitive
• CPC Class Codes: H01Q 1/2208 associated with components used in interrogation type services, i.e. in systems for information exchange between an interrogator/reader and a tag/transponder, e.g. in Radio Frequency Identification [RFID] systems methods or arrangements for sensing record carriers, e.g. for reading patterns G06K7/00; record carrier for use with machines and with at least a part designed to carry digital markings G06K19/00
• CPC Class Codes: H01Q 7/00 Loop antennas with a substantially uniform current distribution around the loop and having a directional radiation pattern in a plane perpendicular to the plane of the loop

Abstract

An RFID device, such as an RFID tag or label, includes a magnetic coupler between an interposer or strap, and an antenna. The interposer or strap includes a transponder chip and an interposer magnetic coupling element that is operatively coupled to the transponder. An antenna portion magnetic coupling element is operatively coupled to the antenna. The magnetic coupling element s together constitute a magnetic coupler that is used to magnetically couple the transponder chip of the interposer to the RFID antenna. A high permeability material may be used to enhance the magnetic coupling between the magnetic coupling elements. The magnetic coupling elements single-turn conductive loops or multiple-turn coils. The magnetic coupler may function as a transformer, with the voltage across the antenna transformed to a different voltage across the transponder chip, and vice versa.

Claims

1. An RFID device comprising:

an antenna portion that includes an antenna;

an interposer having a transponder chip; and

a magnetic coupler magnetically coupling the antenna and the chip.

2. The device of claim 1,

wherein the magnetic coupler includes:

an antenna portion magnetic coupling element electrically coupled to the antenna; and

an interposer magnetic coupling element electrically coupled to the chip; and

wherein the coupling elements are parts of the magnetic coupler.

3. The device of claim 2,

wherein the antenna portion magnetic coupling elements is an antenna portion conductive loop;

and

wherein the interposer magnetic coupling elements is an interposer conductive loop.

4. The device of claim 3, wherein the conductive loops are both single-turn loops.

5. The device of claim 3, wherein at least one of the conductive loops is a multi-turn coil.

6. The device of claim 5, wherein both of the conductive loops are multi-turn coils.

7. The device of claim 5, wherein the antenna portion conductive loop has a different number of turns than the interposer conductive loop, thereby making the magnetic coupler function as a transformer.

8. The device of claim 7, wherein the antenna portion conductive loop has more turns than the interposer conductive loop.

9. The device of claim 7, wherein the antenna portion conductive loop has fewer turns than the interposer conductive loop.

10. The device of claim 3, wherein at least one of the conductive loops has a substantially rectangular shape.

11. The device of claim 3, wherein at least one of the conductive loops has a substantially circular shape.

12. The device of claim 3, wherein the interposer conductive loop is directly electrically coupled to contacts of the chip.

13. The device of claim 12, wherein the interposer conductive loop provides a short circuit between the contacts of the chip.

14. The device of claim 3, wherein the antenna portion conductive loop is directly electrically coupled to the antenna.

15. The device of claim 14, wherein the antenna and the antenna portion conductive loop are a single structure made in a single process operation.

16. The device of claim 3, wherein the antenna portion conductive loop is capacitively coupled to contacts of the chip.

17. The device of claim 3, wherein the antenna portion includes an antenna substrate to which the antenna and the antenna portion coupling element are attached.

18. The device of claim 17, wherein the antenna and the antenna portion coupling element are on respective major surfaces of the antenna substrate, on opposite sides of the antenna substrate.

19. The device of claim 18, wherein the antenna and the antenna portion coupling element are directly electrically coupled together.

20. The device of claim 19, wherein the antenna and the antenna portion coupling element are directly electrically coupled together by conductive material in holes in the antenna substrate.

21. The device of claim 20, wherein the holes in the antenna substrate are punched holes.

22. The device of claim 18, wherein the antenna and the antenna portion coupling element are capacitively coupled together through the antenna substrate.

23. The device of claim 22, wherein the antenna and the antenna portion coupling element include respective pairs of capacitive coupling pads made of conductive material.

24. The device of claim 2, wherein the magnetic coupler includes a high permeability material operatively coupled to the magnetic coupling elements.

25. The device of claim 24, wherein the high permeability material is located at least in part in between the magnetic coupling elements.

26. The device of claim 24, wherein the high permeability material includes a ferrite.

27. The device of claim 24, wherein the high permeability material is part of an adhesive layer adhesively coupling the antenna portion and the interposer.

28. The device of claim 24, wherein the high permeability material is part of a coating covering the antenna portion coupling element.

29. The device of claim 24, wherein the high permeability material is part of a coating covering the interposer coupling element.

30. The device of claim 2, wherein the magnetic coupler compensates for effects of nearby objects on operation of the magnetic coupler.

31. The device of claim 30, wherein the antenna portion magnetic coupling element and the interposer magnetic coupling element cooperatively interact to compensate for effects of nearby objects on operation of the magnetic coupler.

32. The device of claim 1,

wherein the antenna portion includes an antenna substrate to which the antenna is attached;

and

wherein the interposer is attached to the antenna substrate.