Spatially selective UHF near field microstrip coupler device and RFID systems using device
View Patent ↗A system having a UHF RFID transceiver is adapted to communicate exclusively with a single electro-magnetically coupled transponder located in a predetermined confined transponder operating region. The system includes a near field coupling device comprising a plurality of lines connected in parallel with an unmatched load. The near field coupling device may be formed, for example on a printed circuit board with a plurality of electrically interconnected traces and a ground plane. The system establishes, at predetermined transceiver power levels, a mutual electro-magnetic coupling which is selective exclusively for a single transponder located in a defined transponder operating region. Also included are methods for selective communication with the transponder in an apparatus such as a printer-encoder.
1. A method for communication with a plurality of transponders that are configured to move through a transponder operation region, comprising:
transmitting near field RF communication signal, into the transponder operating region;
determining a first signal power level operationally effective to communicate with a first transponder, of the plurality of transponders, disposed in a first position within the transponder operation region;
storing data associated with the first power level and the first position;
determining a second signal power level operationally effective to communicate with a second transponder, of the plurality of transponders, disposed in a second position within the transponder operating region;
storing additional data associated with the second power level and the second position; and
operationally communicating with the remaining plurality of transponders located in the first position and the second position using the data and the additional data to determine power levels and positions of the remaining plurality of transponders region.
2. The method of claim 1 further comprising storing type data for each of the plurality of transponders.
3. The method of claim 1 further comprising moving the first transponder, the second transponder, and the remaining plurality of transponders individually through the transponder operating region.
4. The method of claim 3 , wherein the moving the first transponder, the second transponder, and the remaining plurality of transponders comprises positioning at least one of the first transponder, the second transponder, and the remaining plurality of transponders to avoid a null gap defined by the transmitted near field RF communication signal.
5. The method of claim 4 further comprising storing position information for the at least one of the first transponder, the second transponder, and the remaining plurality of transponders related to avoidance of the null gap.
6. The method of claim 5 further comprising positioning a third transponder disposed in the transponder operating region, based at least in part on the position information for the at least one of the first transponder, the second transponder, and the remaining plurality of transponders, to avoid the null gap defined by the transmitted near field RF communication signal.
7. The method of claim 1 , wherein the transmitting the near field RF communication signal is performed by a near field coupler comprising a one half wave length unmatched transmission line that is configured to transmit the near field RF communication signal from the transmission line edges.
8. A transceiver configured to communicate with a plurality of transponders that are configured to move through a transponder operating region, the transceiver comprising:
a coupler configured to transmit a near field RF communication signal into the transponder operating region; and
a processor configured to:
determine a first signal power level operationally effective to communicate with a first transponder, of the plurality of transponders, disposed in a first position within the transponder operating region;
store data associated with the first power level and the first position;
determine a second signal power level operationally effective to communicate with a second transponder, of the plurality of transponders, disposed in a second position within the transponder operating region;
store additional data associated with the second power level and the second position; and
operationally communicate, via the coupler, with the remaining plurality of transponders located in the first position and the second position using the data and the additional data to determine power levels and positions of the remaining plurality of transponders.
9. The transceiver of claim 8 , wherein the processor is further configured to store type data for each of the plurality of transponders.
10. The transceiver of claim 8 , wherein the first transponder, the second transponder, and the remaining plurality of transponders are moved individually through the transponder operating region by a media conveyance.
11. The transceiver of claim 10 , wherein the moving the first transponder, the second transponder, and the remaining plurality of transponders comprises positioning at least one of the first transponder, the second transponder, and the remaining plurality of transponders to avoid a null gap defined by the transmitted near field RF communication signal.
12. The transceiver of claim 11 , wherein the processor is further configured to store position information for the at least one of the first transponder, the second transponder, and the remaining plurality of transponders related to avoidance of the null gap.
13. The transceiver of claim 12 , wherein the processor is further configured to:
position a third transponder disposed in the transponder operating region, based at least in part on the position information for the at least one of the first transponder, the second transponder, and the remaining plurality of transponders, to avoid the null gap defined by the transmitted near field RF communication signal.
14. The transceiver of claim 8 , wherein the coupler is a near field coupler comprising a one half wave length unmatched transmission line that is configured to transmit the near field RF communication signal from the transmission line edges.
15. A printer configured to print media comprising a plurality of transponders, the printer comprising:
a coupler configured to transmit a near field RF communication signal into a transponder operating region;
a print station configured to print indicia to the media;
a media conveyance configured to move the media through the transponder operating region and the print station;
a processor configured to:
determine a first signal power level operationally effective to communicate with a first transponder, of the plurality of transponders, disposed in a first position within the transponder operating region;
store data associated with the first power level and the first position;
determine a second signal power level operationally effective to communicate with a second transponder, of the plurality of transponders, disposed in a second position within the transponder operating region;
store additional data associated with the second power level and the second position; and
operationally communicate, via the coupler, with the remaining plurality of transponders located in the first position and the second position using the data and the additional data to determine power levels and positions of the remaining plurality of transponders.
16. The printer of claim 15 , wherein the print station comprises a thermal print head and a platen.
17. The printer of claim 15 , wherein the media conveyance is further configured to move the media from the transponder operation region to the print station.
18. The printer of claim 15 , wherein the processor is further configured to store type data for each of the plurality of transponders.
19. The printer of claim 15 , wherein the media conveyance is further configured to:
move the first transponder, the second transponder, and the remaining plurality of transponders individually through the transponder operating region.
20. The printer of claim 19 , wherein the moving the first transponder, the second transponder, and the remaining plurality of transponders comprises positioning at least one of the first transponder, the second transponder, and the remaining plurality of transponders to avoid a null gap defined by the transmitted near field RF communication signal.
21. The printer of claim 20 , wherein the processor is further configured to store position information for the at least one of the first transponder, the second transponder, and the remaining plurality of transponders related to avoidance of the null gap.
22. The printer of claim 21 , wherein the media conveyance is further configured to:
position a third transponder disposed in the transponder operating region, based at least in part on the position information for the at least one of the first transponder, the second transponder, and the remaining plurality of transponders, to avoid the null gap defined by the transmitted near field RF communication signal.
23. The printer of claim 15 , wherein the coupler is a near field coupler comprising a one half wave length unmatched transmission line that is configured to transmit the near field RF communication signal from the transmission line edges.
24. The printer of claim 15 , wherein the media comprises a carrier for supporting a plurality of printable labels, wherein each of the plurality of printable labels comprises one of the plurality of transponders.