Accurate modal representation of arbitrarily shaped multiconductor transmission lines enclosed in homogeneous waveguides

— In this paper, a Green’s function procedure for the complete and accurate TEM modal characterization of multiple conductor systems in homogeneous waveguides is presented. Using this technique, the capacitance and characteristic immittance matrices of almost any multiconductor transmission line can be efficiently computed. In addition, a fast orthonormalization procedure of the TEM modes is described in order to analyze waveguide components including these transmission lines. The technique is tested with several practical examples to prove the accuracy and flexibility of the method proposed.