Transparent UHF-RFID Tag Antenna for IoT Applications

In this paper, a transparent UHF-RFID tag antenna is proposed for seamless integration into smart city IoT applications. The antenna features a transparent radiator made from an Indium Tin Oxide (ITO) conductive film on a glass substrate. The antenna design incorporates a loop structure with a meander line and a T-matching network to match the input impedance of the RFID chip. CST Microwave Studio was used to simulate the antenna performance. A parametric study was conducted to optimize the design and analyze the antenna performance based on different properties of the glass substrate and the ITO film. The proposed RFID tag antenna is designed on a 3mm thick Corning 0080 glass substrate and exhibits a radiation efficiency of 37% with a gain of -2.10dBi. The relatively low radiation efficiency is caused by the high dielectric loss of the glass substrate and the high conductive loss of the ITO film. The proposed design aims for the best possible efficiency of a transparent RFID tag antenna despite the high loss of the materials. Compared to a conventional RFID tag, the proposed transparent tag offers seamless integration with architectural glass structures in smart buildings at the cost of a lower read range. With the length of 0.20 λ
$o$
,the proposed tag antenna is considered electrically small.