A planar ultrawideband (UWB) monopole antenna is proposed in this paper. It has a planar multiple-trapezoidal monopole with adjustable dimensions. The proposed antenna is incorporated with the rectangular/rounded-corner ground plane to further improve the monopole performances such as impedance bandwidth. The geometric complexity of the antenna configuration is not easily devisable when the UWB performance criteria such as low voltage standing wave ratio (VSWR), minimal antenna size, omni-directional and uniform radiation pattern, and relatively constant gain over the ultrawide frequency band are to be simultaneously met. In this paper, all of these requirements can now be easily accomplished by making use of the recently developed jumping genes (JGs) multiobjective optimization scheme. A vivid demonstration of this approach of UWB design is to select an antenna configuration from the thoroughly investigated results and come up with the ultimate recommendation of hardware prototype fabrication. This way not only confirms both the simulated and measured results are all in good agreement but also indicates that the proposed methodology is sound for the design of UWB antenna.