CAD of Waveguide Components for Space Applications Based on Hybrid MMFE Techniques

A hybrid MMFE (Mode Matching Finite Elements) computed aided design technique is presented and its application to the analysis of several space waveguide components is discussed. The novelty of the formulation consists on the expansion of transversal electric and magnetic fields using edge elements. The hybrid approach is the key for an accurate characterization of arbitrary cross-section waveguides, where modal expansions cannot be computed analytically. The results of the analysis of a septum polariser, a square to circular transition and a stepped twist are shown: in all the cases considered the technique proposed has lead to a good agreement between numerical and experimental results with a moderate amount of computing resources.