RFID bridge antenna

• US 7,973,662 B2
• Filed: 12/03/2009
• Issued: 07/05/2011
• Est. Priority Date: 03/23/2006
• Status: Active Grant

• Current Assignee: Xerox Corporation (Xerox Holdings Corp.)
• Original Assignee: Xerox Corporation (Xerox Holdings Corp.)
• Inventors: Phipps, William, Bell, Scott J., Rommelmann, Heiko, Rodriguez, Alberto
• Primary Examiner(s): Lee; Benjamin C
• Assistant Examiner(s): Pham; Lam P
• Application Number:
  US12/630,316
• Publication Number:
  US 20100079253A1
• Time in Patent Office: 579 Days
• Field of Search: 340/539.1, 340/572.1, 340/572.7, 340/572.8, 340/10.1, 340/10.5, 340/825.49, 235/375, 235/385, 235/492
• US Class Current: 340/572.1
• 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 7/0008 General problems related to the reading of electronic memory record carriers, independent of its reading method, e.g. power transfer
• CPC Class Codes: G06K 7/10178 including auxiliary means for focusing, repeating or boosting the electromagnetic interrogation field comparable booster antennas integrated on the record carrier itself G06K19/07794

Abstract

A package for at least two objects includes RFID bridge antennas, having RF antenna elements, for wirelessly communicating data between a tag associated with each object and a reader. An electromagnetic carrier signal transmitted by the reader antenna is received by one of the RF antenna elements and retransmitted to the tag antenna by the other RF antenna element, increasing the distance over which the tag can communicate with the reader. Where the tag is attached to a packaged object, the RFID bridge antenna may be included in the package to allow wireless data communication between the tag and a reader. The reader may also be located external to the package. For example, one of the RF antenna elements may be attached to a label on the package, allowing data stored in the tag to be extracted by the external reader.

Claims

1. A package for at least a first object and a second object each having a tag associated therewith for wirelessly communicating data with a reader, each tag having a tag antenna and the reader having a reader antenna, said package including:

a first RFID bridge antenna, a separate second RFID bridge antenna, and a separate third RFID bridge antenna, each said RFID bridge antenna comprising, in combination;

two RF antenna elements spaced apart from one another and coupled together by an electrical conductor,

said first RF bridge antenna having a first RF antenna element attached to a portion of the package and located proximate to said reader antenna and having a second RF antenna element located proximate to the tag antenna of the first object, the arrangement being such that an electromagnetic carrier signal transmitted by said reader antenna is received by the first RF antenna element and retransmitted by the second RF antenna element to said tag antenna, thereby increasing the distance over which said tag can communicate with said reader,

said second RF bridge antenna having a third RF antenna element attached to a portion of the package and a fourth RF antenna element located proximate to the tag antenna of the second object,

wherein

the reader and the reader antenna are external to said package, and

both the first RF antenna element and the third RF antenna element are readable by said external reader, and

said third RFID bridge antenna having a fifth RF antenna element located proximate to the tag antenna of the first object separate from the second RF antenna element and having a sixth RF antenna element located proximate to the tag antenna of the second object separate from the fourth RF antenna element, said third RFID bridge antenna enabling communication between the tags associated with both objects while the external reader is placed proximate to only one of said RF antenna elements attached to a portion of said package.

2. The package of claim 1, wherein at least one of the first RF antenna element and the third RF antenna element is printed directly onto the exterior surface of said package.

3. The package of claim 1, wherein at least one of the first RF antenna element and the third RF antenna element is mounted onto a substrate which is attached to the exterior portion of said package.

4. The package of claim 3, wherein said substrate is selected from:

a label and a PC board.

5. The package of claim 4, wherein said label is formed at least in part from a conductive ink.

6. The package of claim 1, wherein at least one object includes hardware for electrostatographic printing.

7. The package of claim 1, wherein

in at least one of said first RFID bridge antenna and said second RFID bridge antenna, the RF antenna elements thereof are tuned to a resonate frequency by at least one of stray capacitance in the RFID bridge antenna and capacitance associated with a charge storage element electrically coupled to the RFID bridge antenna, so that in said RFID bridge antenna the RF antenna elements thereof resonate at substantially the same frequency,

the RF antenna element attached to a portion of the package is tuned to approximately the same resonate frequency as the reader antenna, and

the RF antenna element proximate to the tag antenna is tuned to approximately the same resonate frequency as the tag antenna.

8. The package of claim 1, wherein in at least one of said RFID bridge antennas, the electrical conductor comprises a balanced transmission line having a load impedance and a characteristic impedance, the load impedance and the characteristic impedance being substantially equal.

9. The package of claim 1, wherein in at least one of said RFID bridge antennas, the RF antenna elements thereof are electromagnetically coupled together by a low radiation loss RF conductor selected from:

a shielded, flexible, co-axial cable and an open twin lead cable.

10. The package of claim 9, wherein said RF antenna elements are coils formed by one or more loops of electrically conductive material.

11. The package of claim 10, wherein said coils are tuned to a resonate frequency of approximately 13.5 MHz, and conform to ISO Standard 14443-2B.

12. The package of claim 10, wherein at least one of said coils is supported on a substrate.

13. The package of claim 12, wherein the substrate includes at least one of:

a portion of the package, a label for the package and a PC board.

14. The package of claim 1, wherein at least one said tag is secured to hardware for electrostatographic printing, and the hardware for electrostatographic printing is disposed in the package.

15. The package of claim 12, wherein the substrate is a PC board and the electrically conductive coil is embedded within the surface of said PC board.

16. The package of claim 15, wherein at least two electrically conductive coils are embedded within said PC board along with one of:

a low loss, open wire twin lead cable and a strip line electromagnetically coupling said coils together on said board.

17. The package of claim 12, wherein the electrically conductive coil is formed from a conductive ink applied to the substrate.

18. The package of claim 12, wherein the tag is disposed within an object, and the substrate is secured to that object.

19. The package of claim 12, wherein the substrate is proximate to the reader.

20. The package of claim 1, wherein the carrier signal is a radio frequency carrier signal, the tag is a radio frequency identification tag, and the reader is a radio frequency identification reader.

21. A method for increasing a distance over which tags can communicate with a reader, the method comprising:

placing at least a first object and a second object in a package, the first object and the second object having associated therewith a first tag and a second tag respectively;

positioning a first RFID bridge antenna, including a first RF antenna element and a second RF antenna element spaced apart from one another and coupled together by a first electrical conductor, between a first tag antenna of the first tag and a reader antenna associated with the reader so that the first RF antenna element is proximate to the reader antenna and the second RF antenna element is proximate to the first tag,

whereby an electromagnetic carrier signal transmitted by said reader antenna is received by the first RF antenna element and is retransmitted by the second RF antenna element to said tag antenna, increasing the distance over which the first tag can communicate with the reader;

positioning a separate second RF bridge antenna, including a third RF antenna element and a fourth RF antenna element spaced apart from one another and coupled together by a second electrical conductor, between a portion of the package and the second tag, the third RF antenna element attached to a portion of the package and the fourth RF antenna element located proximate to a second tag antenna of the second tag,

wherein the reader and the reader antenna are external to said package, and both the first RF antenna element and the third RF antenna element are readable by said external reader; and

positioning a separate third RFID bridge antenna, including a fifth RF antenna element and a sixth RF antenna element spaced apart from one another and coupled together by a third electrical conductor, between the first tag and the second tag so that the fifth RF antenna element is located proximate to the first tag antenna separate from the second RF antenna element and the sixth RF antenna element is located proximate to the second tag antenna separate from the fourth RF antenna element, the third RFID bridge antenna enabling communication between the tags associated with both objects while the external reader is placed proximate to only one of said RF antenna elements attached to a portion of said package.

22. The method of claim 21, wherein in said first RFID bridge antenna, the RF antenna elements thereof are tuned to a resonate frequency by at least one of stray capacitance in the antenna and capacitance associated with a charge storage element electrically coupled to the antenna, so that said RF antenna elements resonate at substantially the same frequency, the first RF antenna element proximate to the reader antenna is tuned to approximately the same resonate frequency as the reader antenna, and the second RF antenna element proximate to the first tag antenna is tuned to approximately the same resonate frequency as the first tag antenna.

23. The method of claim 21, wherein in each of said RFID bridge antennas, the electrical conductor thereof comprises a balanced transmission line having a load impedance and a characteristic impedance, the load impedance and the characteristic impedance being substantially equal.

24. The method of claim 21, wherein said step of positioning the first RFID bridge antenna and said step of positioning the second RFID bridge antenna each include:

attaching one of the RF antenna elements thereof to a surface on said package and placing the other of the RF antenna elements thereof proximate to the tag antenna associated with said tag.

25. The method of claim 21, wherein the tag is disposed within an object, and positioning the RFID bridge antenna includes attaching one of said RF elements to the object.