Passive Macromodeling of Lossy Multiconductor Transmission Lines Based on the Method of Characteristics

This paper presents an efficient passive macromodeling algorithm for distributed lossy multiconductor transmission lines based on the method of characteristics (MoC). A proof is provided that specifies sufficient conditions to guarantee the passivity of the MoC by construction. A key feature of the proposed algorithm is that the curve fitting to realize the MoC depends only on the per-unit-length (p.u.l.) parameters and not on the discretization of the macromodel. Thus, with the knowledge of the rational functions derived by the p.u.l. parameters, the MoC is formulated in a closed form manner for any line length while ensuring passivity.