Optimization of linear antenna array for low SLL and high directivity

This work focuses on optimal synthesis of a linear array to achieve narrower half-power beam width, reduced side-lobe levels, and nulls control as per the need of the design. To accomplish these goals we considered the optimization of excitation amplitude, phase and inter-element spacing of the array. Since, the optimization problem involved is not convex in nature, so a global optimization algorithm is employed. An effort has been made to optimize the design variables by using Particle Swarm Optimization (PSO), which employed a fitness function defined using null direction and side lobe level (SLL) constraints. It has been shown that for improved array characteristics an appropriate weighted input should be employed and number of elements defining the array should be at least 16.