Pattern synthesis of linear antenna arrays using a genetic algorithm with physical size constraint

Sparse arrays are often employed to reduce the number of antennas used in an array while maintaining a desired spatial resolution and avoiding or reducing the effect of grating lobes. The locations of the antennas in the array affect the beam pattern obtained and they are often optimized by some nonlinear optimisation techniques. This paper presents a method of optimising the antenna locations using a genetic algorithm, while imposing a physical size constraint of the individual antennas. This ensures that the antennas can all physically fit into the locations that result from the optimization process. The fitness value of each individual in the algorithm is calculated based on a least squares formulation. Both multiband and wideband antenna array design examples are provided to show the validity of the proposed method.