Apparatus and method for communicating with an RFID transponder

摘要

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.

主权项

1. A method of communicating with a transponder on a carrier substrate in a printer, comprising:
energizing a transceiver to a plurality of power levels to communicate with the transponder, as the transponder is moving along a media feed path and being disposed at a plurality of distances from the transceiver, wherein: when energized to each of the power levels, the transceiver is configured to generate ultra-high frequency (UHF) signals for near field effect communication with the transponder; and each of the power levels is independent of frequency of the UHF signals; determining rates of successful communication between the transceiver and the transponder for the power levels and for the distances between the transceiver and the transponder; and selecting a first power level associated with a relatively high rate of successful communication between the transceiver and the transponder for a limited range of distances between the transceiver and the transponder.