A Phase-based Method for UHF RFID Gate Access Control

This paper presents a phase-based method for UHF-RFID tag classification in gate access control systems. The proposed system exploits only a single reader antenna and multiple phase samples collecting during the tag motion. Experimental results in real indoor scenario show the method capability to discriminate incoming, outgoing, and passing tag actions. The method can be applied at every identification point equipped with a COTS UHF-RFID system with a software/firmware implementation without requiring additional hardware.