Ultra wideband coplanar waveguide fed spiral antenna for humanitarian demining

A cavity backed coplanar waveguide to coplanar strip fed logarithmic uniplanar spiral antenna, which covers a 9 to 1 bandwidth with a return loss better than 10 dB from 0.4 to 3.8 GHz is presented. A wideband balun covering the frequency range of the antenna was developed. The constructed spiral antenna is very useful in a stepped frequency ground penetrating radar for humanitarian demining due to the very wide band-width, relatively small size, and being uniplanar. Successful detection of a small 5.4 cm non-metallic AP-mines in a pseudo minefield are presented.