RFID device tester and method

• US 7,225,992 B2
• Filed: 02/13/2003
• Issued: 06/05/2007
• Est. Priority Date: 02/13/2003
• Status: Active Grant

• Current Assignee: Avery Dennison Retail Information Services LLC (Avery Dennison Corporation)
• Original Assignee: Avery Dennison Corporation
• Inventors: Forster, Ian J.
• Primary Examiner(s): PAIK, STEVEN SANGYUL
• Application Number:
  US10/367,515
• Publication Number:
  US 20040160233A1
• Time in Patent Office: 1,573 Days
• Field of Search: 235/492, 235/487, 235/380, 235/382, 235/384, 235/383, 235/385, 235/451, 340/572.01, 340/572.07
• US Class Current: 235/492
• 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 7/0095 Testing the sensing arrangement, e.g. testing if a magnetic card reader, bar code reader, RFID interrogator or smart card reader functions properly testing of electrical circuits G01R31/28
• CPC Class Codes: G06K 7/10465 the interrogation device being capable of self-diagnosis, e.g. in addition to or as part of the actual interrogation process testing of electrical circuits in general G01R31/28
• CPC Class Codes: Y10T 29/49004 including measuring or testing of device or component part

Abstract

An RFID device tester includes coupling elements for capacitively coupling a reader to an RFID device to be tested. The reader may power the RFID device by sending an outgoing signal, such as an outgoing AC power signal, which may be rectified and/or reflected by the RFID device, if the RFID device is operating properly. The outgoing signal may have a frequency that is different from the resonant frequency of an antenna of the RFID device. A reader in the RFID device tester detects the reflected and/or transmitted signal to confirm proper operation of the RFID device. The RFID device tester may be used as part of a roll-to-roll process, to individually test RFID devices on a roll of material. By utilizing short-range capacitive coupling, difficulties caused by simultaneous activation of multiple RFID devices may be reduced or avoided.

Claims

1. A method of testing a radio frequency identification (RFID) device, comprising:

capacitively coupling an RFID device tester to an antenna of the RFID device;

generating an outgoing signal from the RFID device tester;

using the outgoing signal to power the RFID device;

generating a return signal in the RFID device;

detecting the return signal, via a reader that is part of the tester; and

prior to the generating the outgoing signal, shifting an optimum operating frequency of the antenna from a natural resonant frequency of the antenna to a shifted resonant frequency;

wherein the generating the outgoing signal includes generating the outgoing signal at a signal frequency that is different from the natural resonant frequency of the antenna;

wherein the shifting the optimum operating frequency includes decreasing the optimum operating frequency;

wherein the decreasing the optimum operating frequency includes overlapping portions of the antenna elements with dielectric elements;

wherein the dielectric elements include a ceramic material; and

wherein the ceramic material includes a material selected from the group consisting of barium tetra titanate and titanium oxide.

2. A method of testing a radio frequency identification (RFID) device on a sheet or roll with other RFID devices, comprising:

capacitively coupling an RFID device tester to an antenna of the RFID device;

generating an outgoing signal from the RFID device tester;

using the outgoing signal to power the RFID device;

generating a return signal in the RFID device;

detecting the return signal, via a reader that is part of the tester; and

prior to the generating the outgoing signal, shifting an optimum operating frequency of the antenna from a natural resonant frequency of the antenna to a shifted resonant frequency that is different from an unshifted natural resonant frequency of the other RFID devices on the sheet or roll;

wherein the generating the outgoing signal includes generating the outgoing signal at a signal frequency that is different from the natural resonant frequency of the antenna; and

wherein the shifting the optimum operating frequency includes increasing the optimum operating frequency.

3. The method of claim 2, wherein the increasing the optimum operating frequency includes bringing electrically-conducting elements in close proximity to antenna elements of the antenna.

4. A method of testing a radio frequency identification (RFID) device, comprising:

capacitively coupling an RFID device tester to an antenna of the RFID device;

generating an outgoing signal from the RFID device tester;

using the outgoing signal to power the RFID device;

generating a return signal in the RFID device; and

detecting the return signal, via a reader that is part of the tester;

wherein the RFID device tester includes coupling elements electrically connected to the reader;

wherein the antenna of the RFID device includes antenna elements;

wherein the capacitively coupling includes aligning the coupling elements with respective of the antenna elements;

wherein the coupling elements are attached to a dielectric layer; and

wherein the aligning includes having portions of the dielectric layer between the coupling elements and the antenna elements.

5. A method of testing a radio frequency identification (RFID) device, comprising:

capacitively coupling an RFID device tester to an antenna of the RFID device;

generating an outgoing signal from the RFID device tester;

using the outgoing signal to power the RFID device;

generating a return signal in the RFID device; and

detecting the return signal, via a reader that is part of the tester;

wherein the RFID device tester includes coupling elements electrically connected to the reader;

wherein the antenna of the RFID device includes antenna elements;

wherein the capacitively coupling includes aligning the coupling elements with respective of the antenna elements;

wherein the coupling elements are part of a roller,

wherein the RFID device is part of a roll material; and

wherein the aligning includes bringing the portion of the roll material having the RFID device into alignment with the coupling elements as the roller rotates.

6. The method of claim 5, wherein the aligning is part of a roll-to-roll process.

7. A method of testing a radio frequency identification (RFID) device, comprising:

capacitively coupling an RFID device tester to an antenna of the RFID device;

generating an outgoing signal from the RFID device tester;

using the outgoing signal to power the RFID device;

generating a return signal in the RFID device; and

detecting the return signal, via a reader that is part of the tester;

wherein the detecting the return signal includes;

capacitively transmitting the return signal from the antenna to coupling elements of the RFID device tester; and

forwarding the return signal from the coupling elements to the reader; and

wherein the forwarding includes forwarding the return signal past a resistor coupled to a pair of transmission lines electrically connecting the reader and respective of the coupling elements.

8. A radio frequency identification (RFID) device tester comprising:

a reader;

a pair of electrically-conductive coupling elements;

a pair of transmission lines electrically connecting respective of the coupling elements to the reader; and

a resistor connected to both of the transmission lines, between the reader and the coupling elements.

9. The device tester of claim 8, further comprising dielectric materials on outer surfaces of each of the coupling elements.

10. The device tester of claim 9, wherein the dielectric materials are portions of a dielectric layer.

11. The device tester of claim 8, wherein the coupling elements are substantially planar.

12. The device tester of claim 8, wherein the coupling elements are hoop-shaped.

13. The device tester of claim 8, further comprising dielectric elements for shifting an optimum operating frequency of RFID devices placed in close proximity to the device tester.

14. The device tester of claim 13, wherein the dielectric elements include ceramic elements.

15. The device tester of claim 8, further comprising additional electrically-conducting elements for shifting an optimum operating frequency of RFID devices placed in close proximity to the device tester.

16. The device tester of claim 8, in combination with an RFID device, wherein the RFID device includes an antenna that is capacitively coupled to the coupling elements.

17. The combination of claim 16, wherein the antenna includes a pair of antenna elements;

and wherein each of the antenna elements is capacitively coupled to respective of the coupling elements.

18. The device tester of claim 8, wherein the coupling elements are part of a roller.

19. The device tester of claim 18, wherein the coupling elements are on an outer surface of the roller.

20. The device tester of claim 19, further comprising additional pairs of coupling elements on the outer surface of the roller, wherein the additional pairs of coupling elements are also coupled to the reader.

21. The device tester of claim 20, wherein the pairs of coupling elements are substantially evenly circumferentially spaced about the outer surface of the roller.

22. In combination, a radio frequency identification (RFID) device and an RFID device tester comprising:

the RFID device, which includes;

an antenna having a pair of antenna elements; and

a chip operatively coupled to the antenna;

the RFID device tester, which includes;

a reader; and

a pair of electrically-conductive coupling elements electrically connected to the reader; and

dielectric materials;

wherein the antenna-elements are each capacitively-coupled with respective of the coupling elements, thereby forming a pair of capacitors; and

wherein the dielectric materials are parts of the capacitors, between the coupling element and the antenna element of respective of the capacitors.

23. The combination of claim 22, wherein the dielectric materials are parts of the RFID device.

24. The combination of claim 22, wherein the dielectric materials are parts of the RFID device tester.

25. The combination of claim 22, wherein the dielectric materials are portions of a unitary dielectric layer.

26. The combination of claim 22, further comprising:

respective transmission lines electrically connecting the coupling elements to the reader; and

a resistor between the transmission lines.

27. A method of testing a radio frequency identification (RFID) device, comprising:

shifting an optimum operating frequency of the device from a natural resonant frequency to a shifted resonant frequency; and

reading the device at a frequency other than the natural resonant frequency;

wherein the shifting include pacing the device in close proximity to shifting elements that shift optimum operating frequency; and

wherein the shifting elements are parts of an RFID device tester that also performs the reading of the device.

28. The method of claim 27, wherein the reading includes capacitively coupling the tester and the device.

29. The method of claim 27,

wherein the testing is performed while the RFID device is on a sheet or roll with other RFID devices;

and

wherein the shifting includes shifting to the shifted resonant frequency that is different from an unshifted natural resonant frequency of the RFID devices on the sheet or roll.

30. A method of testing a radio frequency identification (RFID) device, comprising:

shifting an optimum operating frequency of the device from a natural resonant frequency to a shifted resonant frequency; and

reading the device at a frequency other than the natural resonant frequency;

wherein the shifting include pacing the device in close proximity to shifting elements that shift optimum operating frequency; and

wherein the shifting elements are part of a test fixture that is separate from an RFID device tester that performs the reading of the device.

31. The method of claim 30, wherein the reading includes radio frequency coupling a reader to the device.

32. The method of claim 30,

wherein the testing is performed while the RFID device is on a sheet or roll with other RFID devices;

and

wherein the shifting includes shifting to the shifted resonant frequency that is different from an unshifted natural resonant frequency of the other RFID devices on the sheet or roll.

33. A method of testing a radio frequency identification (RFID) device on a sheet or roll with other RFID devices, comprising:

shifting an optimum operating frequency of the device from a natural resonant frequency to a shifted resonant frequency that is different from an unshifted natural resonant frequency of the other RFID devices on the sheet or roll; and

reading the device at a frequency other than the natural resonant frequency;

wherein the shifting include pacing the device in close proximity to shifting elements that shift optimum operating frequency;

wherein the RFID device includes an antenna with antenna elements; and

wherein the shifting includes at least partially overlapping the antenna elements with the shifting elements.

34. A method of testing a radio frequency identification (RFID) device on a sheet or roll with other RFID devices, comprising:

shifting an optimum operating frequency of the device from a natural resonant frequency to a shifted resonant frequency that is different from an unshifted natural resonant frequency of the other RFID devices on the sheet or roll; and

reading the device at a frequency other than the natural resonant frequency;

wherein the shifting include pacing the device in close proximity to shifting elements that shift optimum operating frequency; and

wherein the shifting includes capacitively coupling the shifting elements to an antenna of the device.