Novel design of star shaped circular fractal antenna

This paper presents the design of a star shaped circular microstrip fractal antenna. This star shaped circular microstrip fractal antenna has been designed on substrate with dielectric constant epsiv_r = 4.3 and thickness h = 1.53 mm. The antenna has been simulated using FDTD technique with dimension a = 40 mm. The simulated result shows the multiple resonances at 0.81 GHz, 1.47 GHz, 2.47 GHz and 3.05 GHz respectively. The first resonant frequency of the fractal antenna is shifted to 0.81 GHz in comparison to conventional circular microstrip antenna resonant frequency 1.41 GHz of same patch size. This indicates the size reduction of the antenna by the applications of the fractal geometry. The antenna has been fabricated and tested. The experimental resonant frequencies of this fractal antenna are at 0.845 GHz, 1.52 GHz, 2.29 GHz, and 3.24 GHz respectively. The simulated and experimental resonant frequencies and radiation pattern are found in good agreement.