Swarm intelligence, one of the newest optimization techniques, was first introduced by James Kennedy and Russell C. Eberhart in 1995.

Kennedy and Eberhart studied the behavior of individuals from the social point of view: individual behavior in groups. PSO simply mimics the success in optimization as a group.

PSO is a stochastic, population based, robust multi-objective search algorithm. It does not require prior knowledge of the shape of the search space.

The algorithm is very simple and easy to implement and PSO has recently been shown to be useful for solving complex electromagnetics and antenna optimization problems.