The study of FSS surfaces with varying surface impedance and lumped elements

The authors develop a preliminary model for the lump-loaded FSS (frequency selective surface) using simple representations for the lumped elements and their interconnections. The representations are derived by applying the resistive boundary condition to include a general surface impedance in the problem formulation. The surface impedance term is then incorporated in the method-of-moments solution and can be varied in each subdomain. A simple lumped-element model is obtained by considering a surface with this type of varying surface impedance to represent the loading. Comparisons of the surface and lumped-load formulations when applied to a four-legged element are shown.<>