Provided is a non-dispersive UWB antenna using multi-resonance, which can obtain a UWB characteristic by combining a monopole radiation patch and stepped open stubs, and can obtain an improved non-dispersion characteristic by using a symmetrical structure of the monopole radiation patch and the stepped open stubs. The non-dispersive UWB antenna includes a dielectric substrate, a monopole radiation patch disposed in the center of the top surface of the dielectric substrate, stepped open stubs connected to the monopole radiation patch to induce multi-resonance, a CPW ground plane, and a CPW feed line connected to the monopole radiation patch. By using the monopole radiation patch, the stepped open stubs, and the CPW feed line, the non-dispersive UWB antenna can obtain the omni-directional radiation pattern in the frequency range (3.1-4.9 GHz) required by the system.