On the Design of CPW- Fed Ultra Wideband Triangular Wheel Shape Fractal Antenna

The new triangular wheel shape (TWS) fractal antenna with CPW - fed is presented. This antenna has been designed on dielectric substrate er = 4.3 and thickness h = 1.53 mm with radius a=40mm. The fourth iterative TWS fractal antenna has been fabricated and tested. The antenna exhibits the excellent ultra wide bandwidth from 0.86 to 11.49 GHz corresponding 172.15 % at S11 < -10 dB. The lower end usable frequency of TWS antenna is shifted to 0.86 GHz in comparison to resonant frequency 1.442 GHz of simple microstrip patch. This reveals the size reduction of the antenna due to fractal properties. The experimental radiation pattern of antenna has been observed nearly omni - directional. The cross polarization of TWS fractal antenna has also been measured. Such type of antenna can be useful for UWB system, mobile and radar applications.