Generation of phase-only pencil-beam pair from concentric ring array antenna using Gravitational Search Algorithm

A pattern synthesis method based on Gravitational Search Algorithm (GSA) is presented to generate a dual pencil beam patterns with two different pre-defined sidelobe levels from a concentric ring array of isotropic antennas. Both the patterns are generated by sharing a common optimum amplitude distribution of the array elements. The pattern with sidelobe level lower than the other is generated by switching phase distribution of the array elements from zero to the optimum value. The amplitude and the phase of the array elements are varied radially along the array using GSA to generate a dual pencil beam of two different sidelobe levels.