Applications of optimization techniques to designs of ultra-wideband planar monopole antennas

Two optimization techniques are respectively applied to the design of ultra-wide band (UWB) planar monopole antennas. They greatly simplify the design procedure, avoiding trial-and-error or one-factor-at-a-time approaches. The first methodology is based on design of experiments (DOE) for size optimization. DOE generates response surface models, which are polynomial functions of the associated geometric parameters, and they can be used for predicting the performance of antennas. The second methodology is based on binary particle swarm optimization (BPSO) for topology optimization. By dividing the metal patch of a planar square monopole antenna into one hundred small square pixels, which can be filled with either metal or air, the corresponding metal/air state of each square pixel is determined by BPSO. A pixelized antenna whose performance meets the design needs is thus obtained. The two methods are respectively applied to the design of an ordinary UWB planar monopole antenna and the associated band-notched design, and they all show excellent performances.