Frequency and time domain hybrid ray-mode-resonance GTD for layered, cavity-coupled and periodic configurations

Summary form only given. In recent studies, the GTD (geometrical theory of diffraction) methodology has been extended to scatterers with surfaces that contain dielectric layers, periodic structures, and aperture coupling to interior cavities. These features require the inclusion of dispersive traveling and resonant mode phenomena in the catalog of the traditional GTD ray species. The outcome is a self-consistent hybrid ray-(traveling mode)-(resonant mode) GTD in the frequency domain, and its wavefront-resonance counterpart in the time domain. The building blocks for this enriched GTD are provided by studies of canonical configurations that include dielectric-covered plane and cylindrical surfaces, infinite and finite periodic arrays, and cavity-backed apertures. The results can be phrased in terms of strongly dispersive surface-guided ray fields, diffracted multiple Floquet-mode ray fields due to global, periodicity, edge scattered ray fields with diffraction coefficients modified by interior loading.<>