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An Equivalent Transmission Line Model Containing Dispersion for High Speed Digital Lines



Alberto Scarlatti, Christopher L. Holloway


The increase in processor speeds in the last few years has created a growing need for the accurate characterization of waveform propagation on lossy printed circuit board (PCB) transmission lines. In 1980, Gumerova, Efimov and Kostenko introduced an equivalent circuit model for analyzing low-frequency propagation of atmospheric discharge on a transmission line over a lossy ground. The present paper will show how this equivalent transmission line model can be used to analyze dispersive transmission lines for high speed digital applications. The equivalent circuit elements of this transmission line model incorporate the frequency dependence of the impedance and admittance per unit length of the transmission line caused by the finite conductivity of the conductors as well as the dielectric losses. We will show that these equivalent circuit elements are such that they are well suited fro easy implementation into finite-difference time-domain (FDTD) transmission line models. Such an FDTD implementation will be presented. S-parameters and pulsed wave-forms for a circular wire, coplanar waveguides (CPW), and microstrip lines are shown.
IEEE Transactions on Electromagnetic Compatibility


equivalent transmission line, high speed digital lines, dispersion


Scarlatti, A. and Holloway, C. (2001), An Equivalent Transmission Line Model Containing Dispersion for High Speed Digital Lines, IEEE Transactions on Electromagnetic Compatibility (Accessed March 2, 2024)
Created October 31, 2001, Updated October 12, 2021