Highly accurate modeling of frequency-dependent balanced transmission lines

Accurate low frequency time domain response of modally decomposable balanced transmission lines are obtained using a modified Marti line modeling. In the proposed modeling, the low frequency fitting of the characteristic impedance function Z/sub c/ (/spl omega/) is modified to fit the short-circuit characteristic of the line. Time domain simulations using the inverse Fourier transform shows the validity of the procedure. As a result, at the same time that the time domain response of the line is improved, the number of poles used in the analytic approximation of the line functions is lowered by a factor of ten compared with EMTP fitting routines.