Radial transmission-line approach for the analysis of ring loaded slots in circular waveguide

Radial transmission-line formalism is a generalization of Marcuvitz-Schwinger theory that permits to solve complex scattering problems in circular geometry. The formalism is exploited in this work for the analysis and design of ring loaded slots in circular waveguide whose applications span from microwave filters to mode converters. The scattering problem is formulated in terms of coupled magnetic field integral equations and solved using novel numerical schemes. The method is applied to study a choke flange and a stub filter in circular waveguide. A comparison with commercial software is reported to confirm the effectiveness of the approach.