UHF RFID Reader Antenna with Four Sub-Arrays for Near-Field and Far-Field Operations

Abstract

A simple UHF RFID reader antenna is designed with four 1×2 Sub-arrays. Measured results show that an impedance bandwidth from 880 to 938 MHz is obtained, which can fully cover the UHF RFID working frequency (902 to 928 MHz). These four Sub-arrays could not only provide four strong E-field distributions around the near-zone region, but also have good far-field radiation patterns within the whole working band. This UHF RFID reader antenna can avoid the risk of tag dislocation in train tracking and positioning system.