Abstract: A method to widen the microwave spectrum with radiating dual-pulse is presented. Based upon this method, a high power ultrawide band dual-pulse radiating antenna is developed. The antenna consists of a half-paraboloidal reflector, a ground plane, and three TEM horn feeds. Simulation analysis and experiments on the antenna are taken. Short-time Fourier transform (STFT) have been conducted to assist with the characterization of the combined pulses. Results show that the combined radiation pulses more effective to widen the microwave spectrum than a single radiation pulse.