Ant colony optimization applied to array thinning

Uniform amplitude arrays on a periodic lattice usually have to be thinned if a low sidelobe level is required. The choice of a thinning configuration has to be performed using an optimization algorithm. If the number of deactivated elements is not kept under control, good array configurations in terms of sidelobe level could result in large losses of directivity. In order to satisfy a constraint on the number of deactivated elements, in this paper the thinning problem is associated to the classical knapsack problem, and the optimization is then performed with an ant colony optimization algorithm. Results for linear arrays are reported. Several thinning configurations, as well as sidelobe level behavior versus the number of deactivated elements, are shown.