Composite spiral antenna with π snowflake fractal PBG structure designed for modern RFID system

Utilizing the advantages of planar equiangular spiral antennas and Archimedean spiral antennas, a composite spiral antenna structure were designed and simulated. Due to the in-phase reflection and photon localization characteristic of PBG structure, the antenna radiation performance could be improved and the bandwidth be broaden. Considering engineering processes, the influences of the substrate´s thickness and dielectric constant, and also different materials on whichRFID tags to be sticked, on the performances of the designed antenna are particularly studied. We also made an antenna sample and measured it. The results show that this antenna has large performance redundancy, good resonant frequency stability and adaptability in high dielectric constant environmental.