Conical circular waveguide with side-coupled rectangular ports analyzed by a hybrid mode-matching/method-of-moment technique

A hybrid mode-matching (MM)/method-of-moment (MoM) technique is presented for the rigorous analysis of the six-port junction of a conical circular waveguide with four side-coupled rectangular waveguides. The effects of the cone and of aperture curvature are rigorously taken into account. The advantage of the conical structure in comparison with its cylindrical counterpart includes achieving additional design potential, which can be applied e.g. for ortho-mode transducers (OMTs) of improved performance. The accuracy and efficiency of the method are verified by comparison with reference values.