Design of double-sided axe-shaped ultra-wideband antenna with reduced radar cross-section

In this study, a novel axe-shaped ultra-wideband (UWB) antenna with low-backscattering radar cross-section (RCS) is designed. The designed UWB antenna bandwidth is 3.4-15.5 GHz covering the entire band assigned for the UWB applications. The RCS of the designed antenna is reduced by modifying the geometrical shape. This technique is based on the subtraction of the metal areas which have the minimum current distributions on the surface of the printed antenna. Therefore the backscattering RCS of the modified axe-shaped UWB antenna is reduced up to 10 dB in the whole frequency band while maintaining the radiation performance. The size of the antenna is 0.32λ_l×0.39λ_l, where λ_l is the wavelength at the lower operation frequency and the fractional bandwidth is 128%. The radiation patterns, scattering characteristics and the RCS of both the modified and reference axe-shaped UWB antennas are simulated and experimentally verified. The simulation and measurement results are in a good agreement.