A multidimensional transfer function model for frequency dependent transmission lines

Measurements of the input impedance of electrical transmission lines indicate a frequency dependency of the line parameters. This behavior can be simulated by adjustments to a suitable transfer function model for frequency independent parameters. To this end, functional transformations in time and space set up a transfer function model as a decomposition into individual modes. Adjusting the parameters for each single mode to measured input impedances faithfully describes the frequency dependent behavior. The presented approach does not only model the input impedance, it is also suitable for time domain simulations.