A Hybrid 2-D/3-D multilevel green's function interpolation method for electrically large multilayered problems

The multilevel Green's function interpolation method has been implemented to solve the general electrically-large multilayered problems. A new hybrid 2-D and 3-D (H2-D/3-D) multilevel interpolation method and a cross-level translation scheme are devised for the specific problems, from which a quad-tree is constructed. The interpolation of the multilayered medium Green's function using radial basis function is then studied. To further accelerate the computation, a subdomain fast Fourier transform scheme and a sparse approximated inverse preconditioner with a new discarding strategy are also incorporated into the algorithm. As numerical examples, typical microstrip antenna arrays, a metasurface antenna and electromagnetic bandgap integrated antenna arrays are analyzed with the proposed method and excellent performance is observed in both accuracy and efficiency.