Abstract—We have extended the linear embedding via Green’s operators (LEGO) method to the solution of complicated struc-tures comprised of many different penetrable and conducting media. By combining LEGO with the Arnoldi basis functions, we are able to substantially reduce the size of the relevant algebraic system that arises from the application of the Method of Moments. We review the basics of the overall approach and we provide examples of validation. Finally, the advantages of LEGO are demonstrated through the solution of the electromagnetic scattering from a complicated two-layer finite-size frequency selective surface. I