Ray-mode analysis of plane wave coupling into a large open circular waveguide

Summary form only given. Previous investigation of high-frequency plane-wave coupling into a wide, open parallel-plate waveguide has been extended for the case of a large open semifinite circular waveguide. Numerical calculation of the internal field distribution revealed the usefulness of the partial sum by significant modes whose longitudinal propagation constants are close to the corresponding values of the incident rays. The diffusion of the initially well-defined incident beam is observed.<>