Time-domain macromodel for nonuniform interconnect analysis

In this article a new method of nonuniform transmission line (NUTL) simulation is proposed. The method is patterned on asymptotic waveform evaluation (AWE). In this paper, the q-pole model is matched to imitate exact position of zeros and poles and values of residues of the poles of admittance matrix of the NUTL. The paper proposes to extend the lossless linear varied transmission line model by elements accounting the phenomenon of energy dissipation. To model the skin effect, author proposed a family of LR ladder circuits, which more and more closely approximate √(s) impedance. To describe dielectric loss the simplest model was used - the model utilizing only one time constant. The result is a line circuit model of nonuniform transmission line scattering energy. This model was verified by comparing the results of measurements of attenuation of RG-58U cable with the results of the Spice simulation.