Synthesis of Flat-top Beam Pattern with a Multiple Concentric Circular Ring Array Antenna

In this paper, the authors describe the synthesis of flat-top beam power pattern for antennas composed of concentric rings of isotropic elements. The synthesis is performed by particle swarm optimization (PSO), varying amplitudes and phases of the elements radially, so as to obtain desired side lobe level and ripple of flat-top beam in the vertical plane. Example illustrates the potential of the method.