Extended RFID tag

• US 20090085750A1
• Filed: 09/27/2007
• Published: 04/02/2009
• Est. Priority Date: 09/27/2007
• Status: Abandoned Application

• Current Assignee: 3M Innovative Properties Company (3M Company)
• Original Assignee: 3M Innovative Properties Company (3M Company)
• Inventors: McGee, James P., Banerjee, Swagata R., Sainati, Robert A., Erickson, David P., Waldner, Michele A.
• Application Number:
  US11/904,625
• Publication Number:
  US 20090085750A1
• Time in Patent Office: Days
• US Class Current: 340/572.700
• CPC Class Codes: B65D 2203/10 Transponders
• 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 19/07767 the first and second communication means being two different antennas types, e.g. dipole and coil type, or two antennas of the same kind but operating at different frequencies
• CPC Class Codes: G06K 19/07786 the antenna being of the HF type, such as a dipole
• CPC Class Codes: G08B 13/2448 Tag with at least dual detection means, e.g. combined inductive and ferromagnetic tags, dual frequencies within a single technology, tampering detection or signalling means on the tag
• 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 9/065 Microstrip dipole antennas patch antenna H01Q9/0407
• CPC Class Codes: H01Q 9/28 Conical, cylindrical, cage, strip, gauze, or like elements having an extended radiating surface; Elements comprising two conical surfaces having collinear axes and adjacent apices and fed by two-conductor transmission lines waveguide horns or mouths H01Q13/00; slot antennas H01Q13/00

Abstract

The invention is directed to an extended radio-frequency identification (RFID) tag. The extended RFID tag includes an ultra-high frequency (UHF) RFID tag having a dipole antenna attached to a first surface of a substrate. The extended RFID tag further includes an antenna extension attached to the UHF RFID tag and overlapping at least a portion of the dipole antenna for electromagnetically coupling the antenna extension and the dipole antenna in operation. The extended RFID tag further includes an insulator positioned between the dipole antenna and the antenna extension to electrically isolate the dipole antenna from the antenna extension.

Claims

1. An extended radio-frequency identification (RFID) tag comprising:

an ultra-high frequency (UHF) RFID tag having a dipole antenna attached to a first surface of a substrate;

an antenna extension attached to the UHF RFID tag and overlapping at least a portion of the dipole antenna for electromagnetically coupling the antenna extension and the dipole antenna in operation; and

an insulator positioned between the dipole antenna and the antenna extension to electrically isolate the dipole antenna from the antenna extension.

2. The extended RFID tag of claim 1, wherein the dipole antenna is positioned between the substrate of the UHF RFID tag and the insulator.

3. The extended RFID tag of claim 1, wherein the substrate of the UHF RFID tag is the insulator positioned between the dipole antenna and the antenna extension.

4. The extended RFID tag of claim 1, wherein at least a portion of the antenna extension extends outwardly from the UHF RFID tag.

5. The extended RFID tag of claim 1, wherein the dipole antenna has two radiators and the antenna extension overlaps at least half of one of the radiators.

6. The extended RFID tag of claim 5, wherein the antenna extension is an elongated rectangle having a length substantially parallel to an axis formed by the two radiators of the dipole antenna and a width substantially perpendicular to the axis formed by the two radiators.

7. The extended RFID tag of claim 6, wherein the length of the antenna extension is at least 4 times greater than a length of a portion of the antenna extension overlapping the dipole antenna.

8. The extended RFID tag of claim 6, wherein the length of the antenna extension is at least 2 times greater than a length of one of the radiators of the dipole antenna.

9. The extended RFID tag of claim 6, wherein the width of the antenna extension is less than a width of the dipole antenna.

10. The extended RFID tag of claim 6, wherein the width of the antenna extension is greater than or equal to a width of the dipole antenna.

11. The extended RFID tag of claim 1, wherein a length of a portion of the antenna extension overlapping the dipole antenna is at least one inch.

12. The extended RFID tag of claim 1, wherein the insulator has a width that separates the antenna extension and the dipole antenna by no more than 5 mil (0.005 inches) for capacitively coupling the antenna extension and the dipole antenna in operation.

13. The extended RFID tag of claim 1, wherein the antenna extension comprises a magnetic security tape for an electronic article surveillance (EAS) system.

14. A radio-frequency identification (RFID) system, comprising:

a storage area for storing an item;

an extended radio-frequency identification (RFID) tag applied to the item;

a transmitter proximate the storage area to produce an electromagnetic field; and

a reader coupled to the transmitter to receive a backscattered electromagnetic signal from the extended RFID tag;

wherein the extended RFID tag comprises an ultra-high frequency (UHF) RFID tag having a dipole antenna attached to a first surface of a substrate, an antenna extension attached to the UHF RFID tag and overlapping at least a portion of the dipole antenna for electromagnetically coupling the antenna extension and the dipole antenna in operation, and an insulator positioned between the dipole antenna and the antenna extension to electrically isolate the dipole antenna from the antenna extension.

15. The RFID system of claim 14, wherein the storage area comprises a shelf having at least one signal line.

16. A method, comprising:

selecting an ultra-high frequency (UHF) radio-frequency identification (RFID) tag having an integrated circuit and a dipole antenna having two radiators coupled to the integrated circuit;

selecting an antenna extension having a length that exceeds a length of one of the radiators of the UHF RFID tag;

applying the antenna extension to the UHF RFID tag to overlap a portion of one of the radiators of the dipole antenna, wherein the antenna extension and the UHF RFID tag together form an extended RFID tag.

17. The method of claim 16, further comprising:

applying the extended RFID tag to an item; and

placing a portion of the extended RFID tag proximate to a reader in an RFID system;

transmitting an electromagnetic field from the reader into an interrogation region of the RFID system;

receiving the electromagnetic field at the extended RFID tag; and

modulating data onto the electromagnetic field in response to the extended RFID tag receiving the electromagnetic field.

receiving a data modulated electromagnetic field at the reader; and

detecting the presence of the extended RFID tag within the interrogation region of the RFID system.

18. The method of claim 16, wherein the antenna extension is applied to overlap at least half of one of the radiators.

19. The method of claim 16, wherein the antenna extension is an elongated rectangle.

20. The method of claim 16, wherein the antenna extension is selected to have a length that exceeds a length of a portion of the antenna extension overlapping the dipole antenna by at least 4 times.

21. The method of claim 16, wherein the antenna extension is selected to have a length that exceeds the length of one of the radiators of the dipole antenna by at least 2 times.

22. The method of claim 16, wherein the antenna extension is selected to have a width less than a width of the dipole antenna.

23. The method of claim 16, wherein the antenna extension is selected to have a width greater than or equal to a width of the dipole antenna.

24. The method of claim 16, wherein the antenna extension is applied to overlap at least one inch of the dipole antenna.

25. The method of claim 16, wherein the antenna extension is applied to provide a separation between the antenna extension and the dipole antenna of no more than 5 mils (0.005 inches) for capacitively coupling the antenna extension and the dipole antenna in operation.