Abstract: An ultra wideband printed dipole antenna fed by microstrip slotline power divider is presented. By properly choosing the location and the size of the open circuit microstrip stub terminated at the end of the microstrip line and the type "U" slots terminated at the ends of the slotline, the signals can be divided equal magnitude (but their phases differ by 180毅)by the series type T junction formed by a slotline and two microstrip lines. The simulation results of the antenna dem onstrate that the impedance bandwidth determined from a 10 dB return loss is across the band 3. 1 ~10. 6GHz. The antenna was fabricated. Experimental results of the antenna show that there is a good agreement between those from simulation and experiment.