Multi-element RFID coupler

• US 8,306,474 B2
• Filed: 11/18/2011
• Issued: 11/06/2012
• Est. Priority Date: 10/31/2005
• Status: Active Grant

• Current Assignee: Zebra Technologies Corporation
• Original Assignee: ZIH Corp. (Zebra Technologies Corporation)
• Inventors: Borisov, Yevgeniy, Torchalski, Karl, Donato, Daniel F.
• Primary Examiner(s): Maung, Nay A
• Assistant Examiner(s): FLEMING-HALL, ERICA L
• Application Number:
  US13/300,311
• Publication Number:
  US 20120108170A1
• Time in Patent Office: 354 Days
• Field of Search: 455/41.1, 340/872.1, 340/686.1, 340/572.1, 340/686.6, 340/686.4, 340/686.8, 340/686.7, 235/375, 358/1.15, 358/1.12
• US Class Current: 455/41.1
• 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 7/10316 using at least one antenna particularly designed for interrogating the wireless record carriers antennas in general H01Q1/22
• CPC Class Codes: H01Q 1/22 by structural association with other equipment or articles
• CPC Class Codes: H01Q 1/2216 used in interrogator/reader equipment
• CPC Class Codes: H01Q 13/206 Microstrip transmission line antennas
• CPC Class Codes: H04B 5/77 for interrogation

Abstract

An RFID communication system comprising a near field coupler that is capable of selectively communicating with a targeted transponder positioned among a group of multiple adjacent transponders. The coupler is configured to receive communication signals from a transceiver and transmit the signals to a targeted transponder in a transponder operating region. The coupler includes a number of radiating elements spaced apart and a switching element. The switching element selectively couples one or more of the radiating elements to the transceiver. The coupled elements transmit the signals into the transponder operating region by emanating a near field effect. The pattern of the near field effect may be adjusted by changing the combination of the coupled radiating elements.

Claims

1. A near field coupler comprising:

a plurality of radiating elements; and

at least one switching element electrically connected to the plurality of radiating elements, wherein the switching element is configured to selectively deactivate one or more radiating elements among the plurality of radiating elements such that a near field effect is produced by the near field coupler in an operating region, the near field effect moving within the operating region to follow the advancement of a targeted transponder.

2. The near field coupler according to claim 1, wherein the at least one switching element is comprised of a plurality of switches.

3. The near field coupler according to claim 2, wherein the plurality of switches includes a number of switches that is equal to or less than a number of radiating elements.

4. The near field coupler according to claim 2, wherein at least one of the plurality of switches is a PIN diode.

5. The near field coupler according to claim 1, wherein the plurality of radiating elements includes three radiating elements and each radiating element is a conductive strip disposed on a first surface of a dielectric substrate.

6. The near field coupler according to claim 1, wherein the plurality of radiating elements are parallel to each other.

7. The near field coupler according to claim 1, wherein the plurality of radiating elements are in a zig-zag configuration.

8. A method of communicating with a targeted transponder, the method comprising:

advancing the targeted transponder along a path;

emanating, into at least a portion of a transponder operating region, a near field effect by controlling one or more radiating elements in the proximity of the targeted transponder in order to communicate with the targeted transponder, wherein the radiating elements are included in a near field coupler that also includes a switching element for selectively deactivating at least one of the radiating elements by decoupling from the at least one of the radiating elements; and

following the advancement of the targeted transponder with the near field effect, the near field effect moving within the transponder operating region by changing the combination of radiating elements that are activated by controlling the switching element based on at least one of an orientation and a location of the targeted transponder within the transponder operating region.

9. The method according to claim 8, wherein controlling the radiating elements includes activating at least one of the radiating elements.

10. The method according to claim 8, wherein controlling the switching element includes controlling of a plurality of switches.

11. The method according to claim 10, wherein the plurality of switches includes a number of switches that is equal to or less than a number of radiating elements.

12. The method according to claim 10, wherein at least one of the plurality of switches is a PIN diode.

13. The method according to claim 8, wherein the radiating elements includes three radiating elements.

14. The method according to claim 8, wherein each of the radiating elements is a conductive strip disposed on a first surface of a dielectric substrate.

15. The method according to claim 8 further comprising determining a power level for each of the one or more radiating elements that accommodates a reliable encoding process between the near field coupler and the targeted transponder.

16. The method according to claim 15 further comprising determining a lowest power level for each of the one or more radiating elements that accommodates the reliable encoding process between the near field coupler and the targeted transponder, wherein the lowest power level is determined for purposes of encoding subsequent transponders arranged in an unknown orientation.

17. A system comprising:

one or more rollers configured to advance a targeted transponder on a path through a transponder operating region; and

a near field coupler comprising;

a plurality of radiating elements; and

at least one switching element electrically connected to the plurality of radiating elements, wherein the switching element is configured to selectively deactivate one or more radiating elements among the plurality of radiating elements such that a near field effect is produced by the near field coupler in an operating region, the near field effect moving within the operating region to follow the advancement of the targeted transponder by the one or more rollers.

18. The system according to claim 17, wherein the at least one switching element is comprised of a plurality of switches.

19. The system according to claim 18, wherein the plurality of switches includes a number of switches that is equal to or less than a number of radiating elements.

20. The system according to claim 17, wherein the plurality of radiating elements includes three radiating elements and each radiating element is a conductive strip disposed on a first surface of a dielectric substrate.