Based on the principle of discone antenna a new UWB monocone antenna is presented. Instead of using traditional cone geometry as a radiator for discone, planar vertical cross strips of aluminum are used as an antenna radiator. This results in wide impedance characteristic and miniaturization of antenna. The simulated model has broadband impedance bandwidth 18 : 1 form 550MHz to 18GHz with Omni directional radiation pattern. The two difierent antenna models are presented in this paper. Design softwares CST Microwave Studio, HFSS and Solid works are used for designing and parametric analysis of antenna. Size reduction up to 45 percent is achieved as compared to tradition discone antenna. The N type panel mount connector is used for antenna feeding. As a result of a low proflle structure, antenna can be easily mounted for portable application. The antenna radiation pattern is measured in anechoic test chamber. The measured results of antenna are found to be in good agreement with simulation results. The features make the antenna highly suitable for UWB applications.