Study of CPW-fed slot antennas with fractal stubs

This paper studies CPW-fed slot antennas with fractal stubs. The S₁₁ bandwidth of the antenna is affected by the fractal stub. It has been found that the antenna bandwidth will decrease when the iteration of fractal stub increases, which it will be opposite to the conventional fractal structures. In this study, fractal models with the 0, 1^st, and 2^nd iterations have been employed, resulting in the S₁₁ bandwidths to be 121%, 115%, and 82%, respectively. Moreover, the radiation patterns of the presented antenna are still bi-directions and the average gains of antenna are above 2 dBi for all of fractal stub iterations. Results indicate an impedance bandwidth covering the band for 3G, WLAN ,and WiMAX.