MLFMA-slotFFT for the electromagnetic solution of densely packed finite periodic structures

The electromagnetic behavior of periodic structures has gained great interest in recent years due to their fundamental role in the development of scattering networks, plasmonic crystals and many other fields related to nanophotonics, including nanoscale and metasurface devices. Linked to this interest is an increasing demand for the development of tools capable of modelling the electromagnetic behaviour of periodic structures as efficiently as possible. In the context of surface integral equation (SIE) methods based on the method of moments (MoM), most of the existing literature has focused on the development of techniques based on the Ewald method, which requires modelling the system with an infinite periodic structure or dealing with complex physical issues to correctly model the edge effects or the standing waves, whose accurate prediction can be critical in some applications.