In this article, a novel spiral fractal monopole antenna is designed to operate in the communication band applications. The performance characteristics like bandwidth, gain and radiation patterns are improved by placing frequency selective surface beneath the antenna structure. A basic model with closed loop ground is designed to operate at multiple frequencies as per the fractal structure. The basic model is modified with deflected ground structure in the monopole fractal configuration to enhance the bandwidth characteristics. Bandwidth is enhanced by double when compared with base model and an impedance bandwidth of 118% is achieved from the modified structure. The FSS is used as a reflector in the modified structure. The FSS is used as a reflector in the modified fractal antenna to enhance the gain characteristics. The complete antenna analysis with modifications in the structure as well as placing of FSS is clearly demonstrated with FEM based HFSS tool. The proposed model is fabricated on FR4 substrate and measured results are furnished along with simulation results for validation purpose. The measured results from ZNB20 vector analyzer are in good agreement with simulation results of HFSS.

frequency selective surface (FSS), spiral monopole, fractal antenna, FR4 substrate, impedance bandwidth, deflected ground structure (DGS).