A Novel Computational Approach for Estimating the Side Lobe Peaks in Non-Uniformly Spaced Linear Antenna Arrays

Optimization of linear antenna arrays with the non-uniformly spaced elements has enticed many researchers and a plethora of literature is available on this subject. This topic received further attention due to the growth of 5G technology and Internet of Things (IoT). This paper presents a restructured mathematical expression of the antenna array factor, for estimating the side lobe peaks. An objective function incorporating the proposed atypical expression is framed and is employed for improved side-lobe reduction using the Genetic Algorithm (GA). The alternate expression for array factor bequeaths with the endowment to predict the angles at which the side lobe peaks occur, thereby curtailing the computational complexity when incorporated by the GA to minimize the side lobes. Simulations are performed for optimizing the radiation pattern using the GA for varying array sizes and for varying constraints on the array inter-element spacing. A comparison of the results affirms the effectiveness of the proposed expression in terms of side-lobe reduction and improved computational efficiency. The proposed expression can be incorporated with other evolutionary algorithms to optimize the radiation pattern.