A novel UWB dual-polarized dielectric horn antenna (DHA) is presented. A DHA consists of four major components - launcher, solid dielectric horn body, feeding structure and background absorber material. The characteristics of this DHA design have been investigated in detail via experiments and FDTD models. This new design is found to provide the desired ultrawide bandwidth, dual-linear polarization, frequency independent radiation patterns, near symmetric E- and H-plane patterns and a stationary radiation (phase) center. Data for a 2-18 GHz prototype are also shown. Further investigation is needed to eliminate the absorber and still not to excite undesired lateral waves. This should improve the gain from its current 0 dBi. A better launcher design is also another challenging topic.