Synthesis of pencil beam pattern with a multiple concentric circular ring array antenna with minimum side lobe level and fixed first null beamwidth

In this paper, the authors present a method based on modified particle swarm optimization for generating pencil beam in the vertical plane with minimum side lobe level and fixed first null beamwidth. The first null beamwidth is made equal to that of a uniformly excited and uniformly spaced multiple concentric circular ring array of same number of elements and same number of rings. The excitation amplitude is radially varied and optimized to achieve the goal. Example illustrates the potential of the method.