In this paper, the authors present an ultra-wideband (UWB) planar antenna with defected ground structure (DGS) for various wireless applications. The operating frequency of the proposed geometry is in the range of 3.1 to 10.6 GHz. The proposed compact geometry antenna is applicable for the UWB applications. In order to optimize the dimensions of the antenna, a parametric analysis has been performed. The measured S11 magnitude is less than-10 dB over the band, and it has an impedance bandwidth of 10.60 GHz. The designed UWB antenna gives maximum radiation efficiency and gain of 96.5% and 3.30 dBi, respectively. Also, it gives good time-domain characteristics over the entire resonating band. The designed UWB antenna is simple geometry, and it is applicable for numerous wireless applications.