The classical Inertia Weight PSO (IWPSO) and Constriction
Factor PSO (CFPSO) are the most common PSO algorithms [19]. The
main de¯ciency of the classical IWPSO algorithm is the premature
convergence when solving multimodal problems. In order to improve
PSO's performance on complex multimodal problems, a variant of
the PSO was proposed [16]. Several antenna design problems are
multimodal and therefore require the use of an optimization method
that does not get trapped easily in a local optimum [18].