“…E. Saenz, K. Guven, E. Ozbay, I. Ederra, and R. Gonzalo have treated in [4] decoupling of multifrequency dipole antenna arrays for microwave imaging applications. Recently, many multiagent stochastic optimization techniques that incorporate random variation and selection, such as evolutional programming(EPs) [6]-7], genetic algorithms (GA) [8]- [9], particle swarm optimization (PSO) [10]- [11], artificial neural network (ANN) [12]- [13], and gradient-based techniques [14]- [15], have been implemented via computer codes. The Vivaldi antenna has been used in many microwave engineering applications for its simple structure, low cross polarization, and highly directive patterns characteristics, especially in ultra bandwidth applications such as vehicular wireless communication, radar imaging, and through-the-wall imaging [16]- [17].…”