Extraction of per-unit-length parameters of transmission lines from measured S-parameters

A method for extracting the per-unit-length parameters of transmission lines from measured S-parameters is presented. The method shows similar results with other methods of calculation of per-unit-length parameters. The maximum deviation of the elements of the matrices of the per-unit-length parameters of single-wire transmission lines is 1,37%, while the minimum value is 0,075%. In the case of multiconductor symmetrical and asymmetrical transmission lines the maximum deviation does not exceed 3,64%. To confirm the results, the characteristics in the time domain are analyzed. It is shown that the method is stable as the complexity of structures increases in terms of the number of conductors and the presence of their asymmetry.