Reflection/transmission coefficient for two-layered dielectric slab with internal multiple reflections

This paper presents novel reflection and transmission coefficients for two-layered dielectric slab, which approximately include multiple reflections inside the slab. H polarization or TE case is here considered. In the derivation, an efficient high frequency approximation is introduced to bundle or collect the multiple reflected rays inside the two-layered slab into the primary ray component. We call them “collective rays”. By utilizing the present reflection/transmission coefficients, one can easily include the internal multiple reflections effect in ray-launching analysis without increase of computational time, so these are very efficient for propagation analysis through indoor/outdoor interface as propagation through multi-layered insulating glass window on side wall of modern building.