Synthetic function expansion with multi-grid approach

A dual-grid scheme for the reduction of the complexity in the full-wave analysis of electrically large and/or complex antennas is addressed. The method starts with the Synthetic Function expansion approach, previously introduced by the authors. Making use of the low pass-filter properties of the Green's function, the distant block interactions could be computed on a coarser grid, reducing the degrees of freedom used for the far field representation. The entire domain basis functions on the coarse grid are obtained by projection of those computed on the dense mesh. As a direct consequence of the proposed scheme, an important reduction in the MoM matrix filling and compression time is achieved, without significantly reducing the accuracy of the final solution on the overall structure.