Sierpinski conical monopole antennas

Planar Sierpinski monopole exhibits a multi-band behavior. However, the parameters of Sierpinski monopole in operation frequency bands are not optimal. The impedance bandwidth is narrow and radiation pattern is not omni-directional in the horizontal plane because of the rotational asymmetry of the planar antenna. These disadvantages can be eliminated by converting the planar Sierpinski monopole to a conical one. By this conversion, a symmetrical three-dimensional (3-D) structure, which reaches a larger bandwidth and a better radiation pattern, is obtained. In the paper, different versions of the conical Sierpinski monopole are proposed, and results of simulations performed in CST Microwave Studio are mutually compared.