Reflection analysis of flanged circular waveguide radiating through small aperture into absorbing medium

A flanged circular waveguide in dominant-mode operation, radiating through a small circular aperture into an absorbing medium, has been studied from the point of view of reflections caused in the guide. The effect of varying the aperture size in modifying the reflections in amplitude and phase has been determined; the proper choice needed to realise matched conditions have been determined for a few selected media.