New high-frequency circuit model for coupled lossless and lossy waveguide structures

A coupled transmission line model describing the two fundamental modes of any two-conductor (above a ground plane or shielded) dispersive or nondispersive lossless waveguide system is given. The model is based on a power-current formulation of the impedances but does not need an a priori supposition about the power distribution over each transmission line. The analysis is extended to lossy structures and to the multiconductor situation. Impedance calculations for a typical coupled microstrip configuration are used to illustrate the approach.<>