RFID tag with enhanced readability

• US 20050093677A1
• Filed: 11/04/2004
• Published: 05/05/2005
• Est. Priority Date: 11/04/2003
• Status: Active Grant

• Current Assignee: Avery Dennison Retail Information Services LLC (Avery Dennison Corporation)
• Original Assignee: Avery Dennison Corporation
• Inventors: Puleston, David J., Forster, Ian J.
• Granted Patent: US 7,298,343 B2
• Time in Patent Office: Days
• US Class Current: 340/10.1
• 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 19/07771 the record carrier comprising means for minimising adverse effects on the data communication capability of the record carrier, e.g. minimising Eddy currents induced in a proximate metal or otherwise electromagnetically interfering object
• CPC Class Codes: G06K 19/07796 arrangements on the record carrier to allow stacking of a plurality of similar record carriers, e.g. to avoid interference between the non-contact communication of the plurality of record carriers
• 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 1/243 with built-in antennas
• CPC Class Codes: H01Q 1/273 Adaptation for carrying or wearing by persons or animals
• CPC Class Codes: H01Q 1/38 formed by a conductive layer on an insulating support patch antennas H01Q9/0407; microstrip dipole antennas H01Q9/065; microstrip slot antennas H01Q13/106; transmission line microstrip antennas H01Q13/206; manufacturing reflecting surfaces using insulating material for supporting the reflecting surface H01Q15/142
• CPC Class Codes: H01Q 13/00 Waveguide horns or mouths; Slot antennas; Leaky-waveguide antennas; Equivalent structures causing radiation along the transmission path of a guided wave
• 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 9/26 with folded element or elements, the folded parts being spaced apart a small fraction of operating wavelength resonant loop antennas H01Q7/00
• CPC Class Codes: H01Q 9/42 with folded element, the folded parts being spaced apart a small fraction of the operating wavelength

Abstract

A radio frequency identification (RFID) device includes a conductive antenna structure having an elongated slot therein. Parts of the antenna structure on both sides of one end of the elongated slot are coupled to a wireless communication device, such as an RFID chip or interposer. On the opposite end of the elongated slot, parts of the antenna structure at both sides of the elongated slot are electrically coupled together, for instance by being coupled together by other conductive parts of the antenna structure. All of the parts of the antenna structure may be parts of a continuous unitary layer of conductive material. The antenna structure with the elongated slot therein may facilitate increased readability of the RFID device, particularly in directions out from the edges of the RFID device.

Claims

1. An RFID device comprising:

an antenna structure having electrically conductive material on both sides of an elongated slot; and

a wireless communication device having a pair of contacts electrically coupled to respective parts of the conductive material;

wherein the parts of conductive material are electrically coupled together at an end of the elongated slot distal from the wireless communication device.

2. The device of claim 1, wherein the antenna structure is on a dielectric substrate material.

3. The device of claim 1, wherein the parts of the conductive material include arms of conductive material.

4. The device of claim 1, wherein the parts are capacatively coupled together.

5. The device of claim 1, wherein the parts are directly electrically connected by a conductive connection.

6. The device of claim 1, wherein the parts and the contact points are directly electrically coupled together by electrically conductive elements.

7. The device of claim 1, wherein one of the parts is capacatively coupled to its corresponding contact point.

8. The device of claim 1, wherein the elongated slot has a substantially rectangular shape.

9. The device of claim 1, wherein the elongated slot has a pair of borders substantially parallel to one another.

10. The device of claim 1, wherein the antenna structure also includes a monopole antenna element coupled to an additional contact of the wireless communication device.

11. The device of claim 1, wherein one end of the elongated slot is short-circuited between the parts, and the other end of the elongated slot is not short-circuited between the parts.

12. The device of claim 1,

wherein the wireless communication device is an RFID chip that is part of an RFID interposer;

and

wherein the RFID interposer includes a pair of conductive leads electrically coupled to the parts of the electrically conductive material.

13. The device of claim 1, wherein the wireless communication device and the antenna structure form an antenna with at least two modes of operation.

14. The device of claim 13, wherein the at least two modes of operation includes two or more modes of operation selected from the group consisting of a mode substantially that of a notch antenna, a mode substantially that of a loop antenna, a mode substantially that of a folded dipole antenna, and a mode substantially that of a slot antenna.

15. The device of claim 1, wherein the wireless communication device and the antenna structure form an antenna having substantially isotropic read characteristics.

16. The device of claim 1, as one of a plurality of RFID devices in close proximity to one another.

17. The devices of claim 16, wherein performance of the RFID devices is enhanced by their close proximity to one another.

18. The devices of claim 17, wherein the RFID devices have an overall size of about 8 cm×

8 cm or less.

19. The devices of claim 18, wherein the RFID devices have an overall size of about 4 cm×

4 cm or less.

20. The devices of claim 16, wherein the devices are in a container.

21. The devices of claim 20,

wherein the container is a carton or box;

and

wherein the devices are mounted to respective objects in the carton or box.

22. The devices of claim 16, wherein the devices are in a display.

23. The devices of claim 16, wherein the devices are coupled to respective bottles.

24. The devices of claim 23, wherein the devices are on caps of the bottles.

25. The devices of claim 23, wherein the devices are on bottom layers of the bottles.

26. The devices of claim 23, wherein the devices are on side layers of the bottles.

27. The devices of claim 16, wherein the devices are in a substantially planar array.

28. An RFID device comprising:

a continuous layer of conductive material with an elongated slot therein; and

an RFID interposer with respective different contact points electrically coupled to the conductive material on the two sides of the elongated slot.

29. A method of communicating with one or more of plural RFID devices, the method comprising:

enhancing performance of the devices by bringing the devices in close proximity to one another; and

communicating with wireless communication devices of the one or more of the devices.

30. The method of claim 29,

wherein each of the devices includes:

an antenna structure having electrically conductive material on both sides of an elongated slot; and

a wireless communication device having a pair of contacts electrically coupled to respective parts of the conductive material; and

wherein the parts of conductive material are electrically coupled together at an end of the elongated slot distal from the wireless communication device.

31. The method of claim 30, wherein each of the devices has an overall size of about 8 cm×

8 cm or less.

32. The method of claim 30, wherein the enhancing readability includes placing the devices in a container.

33. The method of claim 30, wherein the enhancing readability includes placing the devices in a carton.

34. The method of claim 30, wherein the enhancing readability includes placing the devices in a display.

35. The method of claim 30, wherein the enhancing readability includes placing the devices on a shelf.

36. The method of claim 30, wherein the enhancing includes placing at least some of the devices in the vicinity of electrically conductive material.

37. The method of claim 30, wherein the enhancing includes placing at least some of the devices in a substantially planar array.