Circularly polarized high gain Koch fractal antenna for space applications

A compact Koch curve fractal boundary antenna with circularly polarized characteristics is discussed in this article. The radiator is having a square shape with V-slotted truncations along four sides. The operational band of the fractal structure operates at 2.18 GHz to 2.3 GHz band. A 2nd order Koch fractal curve is incorporated along the perimeter of the radiating patch. The fractal antenna is excited by a coaxial probe feeding technique, positioned diagonally for the development of circularly polarized radiation. The patch element is designed using HFSS and also fabricated on a substrate (RT/Duroid 5880 (TM)) having dielectric constant (epsilon(r) = 2.2) is used to design the fractal antenna with dimensions 0.39 lambda(0) x 0.39 lambda(0) x 0.024 lambda(0) (f(r) (=) 2.26 GHz). The structure exhibits a peak gain response of 6.93 dBi along with omnidirectional radiation patterns covering the operational band. The results of simulations and measurements are validated and the presented design is found suitable for space applications.