Numerical Analysis of Planar Periodic Multilayer Structures by Method of Moments

Abstract

Numerical analysis of planar periodic multilayer structures is often carried out with the aid the method of moments (MoM). The advantage of the technique against the other, more general methods (like FEM and FDTD) is in faster computation of reflection and transmission properties of a periodic structure. Besides of computation speed, usage of MoM typically results in lower memory requirements when compared to FEM and FDTD. The method of moments can be either formulated in the spatial or spectral domain. For analysis of periodic structures the spectral formulation is more advantageous ? a discrete space spectrum (Scott, 1989). Thus, the original integral equations reduce into algebraic ones (that is double summations are being used instead of surface integrals). The disadvantage of the spectral formulation is that double summations arising in MoM formulation are slowly convergent and a high number of Floquet modes is needed for analysis of periodic structures having fine patch details inside the period