Thinning of concentric two-ring circular array antenna using fire fly algorithm

Abstract

The paper describes the application of novel meta-heuristics of the fire fly algorithm for reduction of the maximum Side Lobe Level (SLL) with specific First Null Beam Width (FNBW) of thinned two-ring Uniform Concentric Circular Arrays (UCCA) of isotropic elements. The effect of thinning is analyzed in the four subsequent examples using uniform and non-uniform excitations for different FNBW. Optimization is carried out without and with prefixing the value of the percentage of thinning. The UCCA containing 35 and 70 elements in the two successive concentric rings is optimized using FFA. The example using non-uniform excitation is proved more efficient to reduce SLL for same FNBW. Simulation results show the SLL performance improves as we chose the FNBW wider in the designing problem. Fixing the percentage of thinning at a higher value increases the power efficiency of the feeding network with little compromise on the design specifications. The non-uniformly excited thinned concentric array is again optimized using two more state-of-the-art algorithms, namely, Particle Swarm Optimization (PSO) and Differential Evolution (DE) to compare the effectiveness of each algorithm in a statistically meaningful way. Design results using fire fly algorithm shows better performances compared to PSO and DE provided the same number of function evaluation has been considered for all the algorithms.