The optimal synthesis of concentric elliptical antenna arrays

Abstract

ABSTRACTIn this paper, firstly, a common mistake in the formulation of the array factor of concentric elliptical antenna array (CEAA) is pointed out and corrected. Secondly, several CEAAs are optimally designed to have the smallest sidelobe level (SLL). This is accomplished using four optimisation algorithms; Antlion Optimisation algorithm (ALO), Grasshopper Optimisation Algorithm (GOA), Symbiotic Organisms Search (SOS) and a newly proposed hybrid algorithm based on ALO and GOA. Two cases for CEAA synthesis are presented. The goal in the first case is to find the optimal values for the current amplitudes (’s) to minimise the sidelobe level, assuming that the antennas’ positions are fixed along the ellipses. In the second case, the current amplitudes (’s) are assumed to be unity, and the optimisation problem is to find the optimal values for the elements positions along the ellipses. The results of the proposed optimisation algorithms are compared to uniform antenna array results.