METHOD AND APPARATUS FOR DETERMINING THE DIRECTION OF MOVEMENT OF RFID TAGS AND FOR CREATING CONSTANT-WIDTH INTERROGATION ZONES

摘要

[0047] The disclosed inventions relate to a method and apparatus for creating one-sided interrogation zones. The disclosed inventions further relate to a method and apparatus for determining the direction of movement of tagged items that pass by an RFID reader. The disclosed inventions also relate to a method and apparatus for combining one-sided interrogation zones of two or more antenna arrays to create an interrogation zone that maintains its width over a large range of distances.