Design of thinned concentric circular antenna arrays using firefly algorithm

Firefly algorithm (FA) is a nature inspired computing algorithm based on the behaviour of fireflies. It is a kind of stochastic meta-heuristic algorithm that can be used for various engineering optimisation problems. This study presents application of FA for the design of thinned multiple concentric circular antenna arrays. The aim is to achieve an array of uniformly excited isotropic elements that will generate a pencil beam pattern in the vertical plane with minimum side lobe level (SLL). Two different cases have been considered in this study for thinning of concentric circular (ring) arrays using FA. The first case is with uniform inter-element spacing fixed at 0.5λ or its multiple and the second case with optimum inter-element spacing or its multiple. The thinning percentage of the array is kept equal to or more than 50% and the beamwidth is kept equal to or less than that of a fully populated, uniformly excited and 0.5λ spaced ring array of same number of elements and rings. The results obtained are compared with previous published results, which show the effectiveness of this approach.