Propagation through a window frame structure at outdoor/indoor interface environment

This paper examines specific propagation characteristics for a simple outdoor/indoor interface environment, by analyzing diffraction problem for wide aperture slit in an infinitely long PEC screen. High frequency asymptotic ray technique is applied to analyze the diffraction problem. According to the ray-mode coupling analysis, the total diffracted or radiated field in each region is considered as a summation of successive modal radiation contribution due to the original modal excitation by the incident plane wave. The successive process for generating internal higher modal reflection and external modal radiation fields continues until all the energy inside the slit region is completely consumed. The validity of the derived solution is confirmed by comparing with the other analytical reference one for both width and thickness variations.