A novel coplanar waveguide (CPW) fed slot antenna for ultra-wideband (UWB) short range impulse radar systems is presented. A floating metal layer on the bottom of the antenna’s substrate is used to realize the one-sided directional radiation and high gain. The antenna’s dimensions are optimized to achieve impedance bandwidth of 7.8-9.2GHz. The final size of the antenna is 29mm × 16mm × 1.6mm. The proposed antenna is simulated, fabricated, and measured while a good agreement between the simulation and measurement results is obtained.