POWERING RFID TAGS USING MULTIPLE SYNTHESIZED-BEAM RFID READERS

摘要

Synthesized-beam RFID readers may be used to manage and provide information about RFID tag populations. In one embodiment, two or more synthesized-beam readers synthesize respective RF beams towards a tag location. The synthesized-beam readers may coordinate their pointing by means of a controller, a peer-to-peer network, or by using a master-slave arrangement. The synthesized-beam readers may coordinate their transmissions to increase the RF energy available to a tag at the pointing location.

主权项

1. A method for inventorying a Radio Frequency Identification (RFID) tag comprising:
communicating, from a controller, a target location to a first synthesized-beam RFID reader and to a second synthesized-beam RFID reader, steering, responsive to the communicated target location, a first beam from the first synthesized-beam reader to the target location and a second beam from the second synthesized-beam reader to the target location; transmitting, simultaneously, from the first synthesized-beam reader a modulated RF inventory signal and from the second synthesized-beam reader a substantially unmodulated RF signal; receiving, responsive to the modulated RF inventory signal, a tag reply at one of the first and second synthesized-beam readers; and transmitting, from one of the first and second synthesized-beam readers, a modulated RF acknowledgment signal responsive to the tag reply, and from the other of the first and second synthesized-beam readers a substantially unmodulated RF signal.