Radial-line/coaxial-line junctions: analysis and equivalent circuits

An exact analysis of a radial-line/coaxial-line junction is presented. An equivalent is deduced for the junction for the case where only the dominant modes can propagate in the radial and coaxial lines. The expressions for the equivalent circuit are in terms of the unknown coaxial aperture electric field. It is shown that only one component of the equivalent circuit is affected to any extent by approximation of the aperture field. Expressions for the equivalent circuit are then obtained using the TEM approximation. Finally, two modified junctions are considered.