Design a Microstrip UHF RFID Tag Antenna for Metallic Object Application

Abstract

Deploying an RFID syitem on metallic object can present mary challenges, the most challenging isue is that to have the antenna high gain, litie reflection coefficient, and smalil size. The performance of RFID tag antennas can be improved using mctamuteriah. Some recent works have pointed out that metamaterial hased antenna can have the same characteristlcs as large printed antenna. The project represents the proposed splia-ring resonator based UHF RFID tag antennas with regular ground plane and photonic bandgap ground plane for metallic applicat ion in the 917 MiHz with high gain and appropriste reading range, the sire of the tag antenna bs 84.5-61.8-1.57 mm, which is placed on PIFE substrate with thickness 15 mm PBG structure is formed by placing any periodic shapes in the ground of the tag antenna, in this projsct periodic circkes were placed in the ground of the tag antena After studying the PBG strcture by trying different values of the diameters of the cireles and the distance between these circles note that the effect be on the resonance frequencies witout any improvement on the gain of the antenna, So try'ing periodic cirgles to orm PBG did not help to improve the gain, may be different shapes rather than circles did that The gain of SRR based tug antenna with regular ground pline is - 1.43 dB when it placed on 400 400 mm2, but in the end of the project we note that the gain of the regular ground plane is always nejative so to enhance this gain the parameters that constituent the antencu have been studied and we found that when the value of the parameter S reduced from 0.2 mm to 0,10 mm the gain of the antenna enhanced from-1.43 dB to 0,0563 4B when the antenna placed on 400 400 mm2