RFID device with combined reactive coupler

• US 20060043198A1
• Filed: 09/01/2004
• Published: 03/02/2006
• Est. Priority Date: 09/01/2004
• Status: Active Grant

• Current Assignee: Avery Dennison Retail Information Services LLC (Avery Dennison Corporation)
• Original Assignee: Avery Dennison Corporation
• Inventors: Forster, Ian J.
• Granted Patent: US 7,158,033 B2
• Time in Patent Office: Days
• US Class Current: 235/492
• 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 19/07752 using an interposer
• CPC Class Codes: G06K 19/07756 the connection being non-galvanic, e.g. capacitive
• CPC Class Codes: G06K 19/07786 the antenna being of the HF type, such as a dipole
• CPC Class Codes: H01Q 1/2225 used in active tags, i.e. provided with its own power source or in passive tags, i.e. deriving power from RF signal
• CPC Class Codes: H01Q 5/40 Imbricated or interleaved structures; Combined or electromagnetically coupled arrangements, e.g. comprising two or more non-connected fed radiating elements
• 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
• CPC Class Codes: H01Q 9/285 Planar dipole H01Q9/065 takes precedence; patch antenna H01Q9/0407

Abstract

An RFID device, such as an RFID tag or label, includes a combined reactive coupler electrically coupling a transponder chip to an antenna. The combined reactive coupler includes a magnetic coupler and a capacitive coupler. The magnetic coupler and the reactive coupler may have respective coupling elements on both the interposer and on an antenna substrate.

Claims

1. An RFID device comprising:

a pair of components; and

a combined reactive coupler electrically coupling together the components, wherein the combined reactive coupler includes;

a magnetic coupler; and

a capacitive coupler.

2. The device of claim 1,

wherein one of the components is on a substrate;

and

wherein the other of the components is on an interposer that is mechanically coupled to the substrate.

3. The device of claim 2,

wherein the component on the substrate is an antenna, with the substrate and the antenna being parts of an antenna portion;

and

wherein the component on the interposer is a transponder chip.

4. The device of claim 3,

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.

5. The device of claim 4,

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.

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

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

8. The device of claim 7, wherein both of the conductive loops are multi-turn coils.

9. The device of claim 7, 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.

10. The device of claim 5, wherein the interposer conductive loop is directly electrically coupled to contacts of the chip.

11. The device of claim 10, wherein the interposer conductive loop provides a short circuit between the contacts of the chip.

14. The device of claim 5, wherein the antenna portion conductive loop is capacitively coupled to contacts of the chip.

15. The device of claim 4, wherein the magnetic coupler includes a high permeability material operatively coupled to the magnetic coupling elements.

16. The device of claim 15, wherein the high permeability material is located at least in part in between the magnetic coupling elements.

17. The device of claim 15, wherein the high permeability material includes a ferrite.

18. The device of claim 15, wherein the high permeability material is part of an adhesive layer adhesively coupling the antenna portion and the interposer.

19. The device of claim 15, wherein the high permeability material is part of a coating covering the antenna portion magnetic coupling element.

20. The device of claim 15, wherein the high permeability material is part of a coating covering the interposer magnetic coupling element.

21. The device of claim 4, wherein the magnetic coupler compensates for effects of nearby objects on operation of the magnetic coupler.

22. The device of claim 21, 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.

23. The device of claim 3, wherein the capacitive coupler includes:

an antenna portion pair of capacitive coupling elements that are electrically coupled to the antenna;

an interposer pair of capacitive coupling elements that are electrically coupled to the transponder chip; and

a dielectric material between the pairs of capacitive coupling elements.

24. The device of claim 23, wherein the capacitive coupling elements each include areas of conductive material.

25. The device of claim 23, wherein the dielectric material includes an adhesive between the pairs of capacitive coupling elements.

26. The device of claim 23, wherein the capacitive coupler compensates for effects of nearby objects on operation of the capacitive coupler.

27. The device of claim 26, wherein the antenna portion capacitive coupling elements and the interposer capacitive coupling elements cooperatively interact to compensate for effects of nearby objects on operation of the capacitive coupler.

28. The device of claim 23, wherein the magnetic coupler compensates for effects of nearby objects on operation of the magnetic coupler.

29. The device of claim 3, wherein the antenna includes compensation elements.

30. The device of claim 1, wherein the magnetic coupler and the capacitive coupler each transmit at least 10% of the energy transmitted between the components.

31. The device of claim 1, wherein the device further comprises an adhesive layer between the components.

32. The device of claim 31, wherein the components include a chip and an antenna.

33. The device of claim 32, wherein the adhesive layer includes a pressure sensitive adhesive.

34. The device of claim 32, wherein the reactive coupler is relatively invariant to thickness of the adhesive layer.

35. The device of claim 34, wherein tuning frequency of the reactive coupler has less than about 1% variance for variations in thickness of the adhesive layer from 10 μ

m to 35 μ

m.

13. The device of claim 5, wherein the antenna portion conductive loop is directly electrically coupled to the antenna.

13-1. The device of claim 12, wherein the antenna and the antenna portion conductive loop are a single structure made in a single process operation.

36. An RFID device comprising:

an antenna portion that includes an antenna substrate, and an antenna on the antenna substrate;

an interposer mechanically coupled to the antenna portion, wherein the interposer includes a transponder chip; and

a combined reactive coupler electrically coupling together the antenna and the transponder chip, wherein the combined reactive coupler includes;

a magnetic coupler; and

a capacitive coupler;

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 capacitive coupler includes;

an antenna portion pair of capacitive coupling elements that are electrically coupled to the antenna;

an interposer pair of capacitive coupling elements that are electrically coupled to the transponder chip; and

a dielectric material between the pairs of capacitive coupling elements.