Simultaneous Multi-beam Forming Method for Planar Array based on Improved Gravitational Search Algorithm

In this paper, an improved gravitational search algorithm (IGSA) is proposed for the requirements of the simultaneous multi-beam forming (SMBF) of large scale planar array. Here, the SMBF of large scale planar array is viewed as an optimization problem with excitation amplitudes and phases being the optimization variables, attaining sidelobe suppression, pencil beams and high gains being the optimization objectives. For this optimization problem, IGSA is introduced, and the adaptive modified particle structure is used to enhance the capability of global explorating, which further improves IGSA's performance. For this multi-objective optimization problem, inverse gradient weighting operation is used to enhance the capability of multi-objective optimization. Finally, IGSA is verified in simulation experiments of the SMBF of planar array, and the results are compared with other excellent random optimization algorithms. The results demonstrate that the proposed IGSA is superior to other algorithms in the SMBF of planar array performance with a lower sidelobe level, more satisfactory pencil beams and higher gains and realizes SMBF for 100–200 array elements while performance of other algorithms is insufficient.