A Novel UHF Near-Field RFID Reader Antenna Deploying CSRR Elements

A novel ultrahigh frequency (UHF) near-field radio-frequency identification (RFID) reader antenna based on the complementary split ring resonator (CSRR) elements is presented in this communication. The antenna consists of a power divider and two arms. The two arms are terminated with two 50-Ω terminations. First arm is forward arm, which is a microstrip transmission line. The second arm is backward arm, which is loaded with CSRR elements, instigating backward wave propagation. The oppositely directed currents are generated by this configuration to produce strong and uniform magnetic field over the antenna plane for UHF near-field RFID operations. The proposed antenna operates from 0.76 to 0.88 GHz, and a total impedance bandwidth of 120 MHz is obtained. A near-field read range of 100 mm and an interrogation area of 220 mm × 180 mm over the antenna plane at a height of 50 mm is reported for this antenna.