Intelligent z-plane boundary condition-particle swarm optimiser for small array pattern synthesis

This study concerns the radiation performance improvement of small periodic linear phased arrays in the presence of mutual coupling. An approach using a particle swarm optimiser (PSO) coupled with Schelkunoff´s z-plane unit circle is proposed, with z-plane zeros constrained using adaptive boundary conditions (termed the intelligent z-plane boundary condition-PSO). It is shown that the proposed optimisation scheme has successfully achieved the target results for a range of problems presented including low-sidelobe scanned beam, and sector-beam pattern synthesis. The approach has consistent and faster convergence when compared with competitive techniques. Results showing significant improvement are presented using a Bowtie dielectric resonator antenna and uniform hemispherical elements.