Abstract-A compact printed ultra-wideband (UWB) antenna with band-notched characteristic is proposed. The presented antenna consists of a modified ground plane structure and a novel C-shaped radiation patch fed by a microstrip line. By etching a C-shaped slot in the radiating patch, the notched band of 3.3-3.8 GHz for WiMAX is generated. The notched band can be easily tuned by controlling the size of the slot. The measured results show that the proposed antenna operates over a wide bandwidth from 3 GHz to 16 GHz with return loss less than −10, except a stop-band of 3.3-3.8 GHz. Some key parameters of the antenna are discussed in details. The time-domain characteristics are given.