Abstract
This paper applies a constant, real modal transformation matrix to delay-less rational modeling of multi-conductor interconnects. The modeling boils down to fitting and passivity enforcement of eigenvalues rather than the full admittance matrix, thereby giving an efficient and robust approach. Usage of vector fitting (VF) with inverse magnitude weighting gives a high relative accuracy of the eigenvalues, similarly as with Modal Vector Fitting (MVF). The modal formulation is included in the time domain simulation, leading to very fast computations, compared to a pole-residue model. For the two investigated four-conductor interconnect examples, the error incurred by the assumption a constant transformation matrix is small. Copyright IEEE