Mutual coupling between two waveguide radiators on a conducting concave sectoral surface

In the reported investigation Rumsey's reaction concept has been used to solve the mutual coupling problem for the case in which the two waveguide radiators opening into a locally plane surface are partially looking into each other. The problem is formulated and expressions for mutual admittance are derived separately for E- and H-plane coupling. The obtained expressions are applied to the particular case of coupling between two radiators directed radially inward and situated on a circularly cylindrical surface. The derived relations, which involve an integro-differential expression, are not integrable in the closed form. The results obtained by means of numerical computation agree closely with experimental data.