Electromagnetic analysis of UHF near-field RFID tag antenna

Abstract : In this paper, the performance of Near-Field UHF RFID systems is investigated by means of electromagnetic analyses. A novel antenna is presented for ultra high frequency (UHF) near-field radio frequency identification (RFID) applications. The reactance component of tag antenna considered chip impedance (-193j) is conjugated and matched for maximum power transmission. The antenna is fabricated by using Polyester (PET) dielectric substrate with permittivity 3.2. The size of antenna is 38 × 18 × 0.5 mm. The HFSS simulator is used for optimizing the proposed antenna. The antenna Return Loss is of 14.0 dB for the worst case in the middle of UHF range, better than 31.4 dB at 900 MHz.