Wedge Waveguide with Nonpenetrable Boundaries

Many natural or man-made guiding environments are characterized by physical parameters that render the wave equation nonseparable in any of the standard coordinate systems. Adiabatic modes (AMs) fail in cutoff regions and can be uniformized there by intrinsic modes (IMs), which are synthesized by a spectral continuum of AM. In this chapter, the problem, in general, is defined and formulated. A special test case of a wedge waveguide with nonpenetrable boundaries, under line source excitation (Green's function (GF) problem), is formulated and solved rigorously (in cylindrical coordinates) and approximately in terms of local rectangular mode superposition. The chapter then describes a self-contained MATLAB-based visualization package WedgeGUIDE. Numerical tests and illustrations are also presented, followed by a discussion on the method of moments (MoM) modeling.