Improved Per-Unit-Length Parameter Definition for Non-Uniform and Lossy Multiconductor Transmission Lines

A novel, practicable and accurate approach for the definition of the per-unit-length (p.u.l.) parameters of a nonuniform and lossy multiconductor transmission line (MTL) is presented. The reviewed derivation of the transmission line (TL) equations reveals that the commonly used parameter definition can be improved by taking into account the trajectories of the TLs. The revised p.u.l. parameters can be used for an arbitrary MTL model. The comparison to an elaborate fullwave 3D simulation and the TL-solution with the commonly used p.u.l. parameter definition demonstrates the improved accuracy in frequency and time domain.