Efficient Method of Moments Analysis of Periodic Metasurfaces Combining Spectral and Spatial Domain Approaches

This paper presents an efficient Method of Moments (MoM) formulation for the analysis of periodic metasurface (MTS) antennas. Whereas the periodic MoM matrix can be computed in spatial or spectral domains, its slowly convergent behavior in both domains directly impacts its computation time. In this work, it is proposed to accelerate the MoM matrix computation time through an appropriate combination of spectral and spatial domain approaches. This will be particularly well suited for the analysis of embedded element patterns of infinite periodic structures as the latter can be obtained using the periodic MoM for each direction of observation. Validation results are shown for two different MTS implementations, with details of the computation times.