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

摘要

A radio frequency (RF) identification (RFID) tag reading system and method accurately 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 by transmitting a primary transmit signal to each tag, and steering a primary receive beam at a primary steering angle by receiving a primary receive signal from each tag. The controller thereupon steers a plurality of secondary receive offset beams at different secondary steering angles that are offset from the primary steering angle by receiving secondary receive offset signals from each tag, and by processing the offset signals to determine a true bearing for each tag.