Design and analysis of miniature fractal antenna

Fractal antenna designs can meet most of the needs in size reduction of antenna design. In this paper, Koch iteration technique is applied to a dipole antenna in order to get a miniaturized radar array element. The dipole antenna with 3rd Koch iteration applied to each of its four segments is designed to operate at a resonant frequency of 500 MHz. The four fractal segments of this antenna spin around the center axis with an angle difference of 90 degrees each, which results to an all-four-direction feature. The overall size of this dipole fractal antenna at the resonant frequency is reduced by around 33% compared with conventional dipole antenna meanwhile retaining its band characters. An improved model is also introduced with a better performance in bandwidth, which can reach more than 12% at 500 MHz.