System for and method of rapidly determining true bearings of radio frequency identification (RFID) tags associated with items in a controlled area

摘要

An RFID tag reading system and method accurately and rapidly determine true bearings of RFID tags associated with items in a controlled area. An RFID reader has an array of antenna elements and a plurality of RF transceivers. A controller controls the transceivers by steering a primary transmit beam over the controlled area to each tag, by steering a primary receive beam at a primary steering angle from each tag, by steering a plurality of secondary receive beams at different secondary steering angles that are offset from the primary steering angle by receiving secondary receive signals from each tag, and by processing the secondary receive signals to determine a true bearing for each tag. Bidirectional communication between the reader and a tag is conducted over a single inventory round in which the tag is read a plurality of times by the primary and the secondary receive beams.