Extension of the forward-backward method using spectral acceleration for the fast analysis of large array problems

The analysis of large array problems has been a very difficult task because of the limitations of available numerical methods such as the method of moments (MoM), especially in the situation where nonperiodic structures are present. The approach of the forward backward method using the novel spectral acceleration (FBM/NSA) algorithm, previously developed for the modelling of scattering problems from large rough surfaces, has tremendous potential to overcome the current limitations in exact numerical studies. The extension of this FBM/NSA approach with O(N) in computational complexity is presented for treating large array problems. Similarly to its applications in rough surface problems, the efficiency and accuracy of this approach are validated and demonstrated by numerical results in comparison with rigorous MoM solutions.