Scattering analysis of FSS reflectors using Huygen´s principle

The scattered fields from an illuminated FSS (frequency selective surface) reflector are formalized using Huygen´s principle in such a way that the reflection and transmission cases are treated identically. A physical optics approach is used to obtain the scattered fields from equivalent electric and magnetic surface currents on the surface of the FSS reflector. The equivalent surface currents on the curved FSS geometry are approximately obtained using local reflection/transmission matrices of the FSS. It is demonstrated that the approach described here reduces to the approach of D. Bresciani and S.Contu (1985) in the case of an electrically thin FSS. In the transmission case the advantages of the approach described here are that only integration over the FSS reflector surface is required and that the scattered field represents a modification to the illuminating field. An example using a planar FSS reflector is presented.<>