System for, and method of, accurately and rapidly determining, in real-time, true bearings of radio frequency identification (RFID) tags associated with items

摘要

A radio frequency identification (RFID) tag reading system and method accurately and rapidly determine, in real-time, true bearings of RFID tags associated with items in a controlled area. Primary transmit and receive beams are steered over the area, and multiple secondary receive beams are substantially simultaneously steered to a plurality of bearings in the area. The highest signal strength of secondary receive signals from the secondary receive beams determines an approximate tag bearing of each tag. Two secondary receive beams at opposite sides of the approximate tag bearing in elevation are selected to obtain a pair of elevation offset signals, and two secondary receive beams at opposite sides of the approximate tag bearing in azimuth are selected to obtain a pair of azimuth offset signals. The elevation offset signals and the azimuth offset signals are processed to determine a true bearing for each tag in real-time.