A fractal ultra-wideband loop-dipole composite antenna

Abstract

A compact wideband fractal loop-dipole composite antenna is presented. By introducing a Koch fractal structure, the antenna's size can be reduced while maintaining good pulse fidelity. It is demonstrated that an impedance bandwidth from 2.86 to 11.23GHz for |S 11 | lower than -10dB could be obtained. Furthermore, stable radiation pattern and pulse fidelity of 0.75 could be achieved in the same bandwidth.Index Terms-Wideband antenna, fractal, compact, loopdipole composite antenna.I.