Frequency dependent and nonuniform parameters transmission line model

The paper presents a fast and effective method of modeling a nonuniform and dispersive interconnect with frequency dependent parameters. The model uses the S-parameters. The approach is based on the method of successive approximations. The per-unit-length parameters frequency dependence is taken to account by means of the rational approximation - vector fitting. Then the first order approximation of the scattering parameters is calculated. The first order approximation of the S12, S21-parameters is corrected by using second order approximation. Comparisons of the calculated results with the exact one are performed for the Bessel dispersive transmission line.