METHODS FOR PARAMETRIZATION OF TRANSMISSION LINE STRUCTURES ON PRINTED CIRCUIT BOARDS AND OTHER DIELECTRIC SUBSTRATES

摘要

This paper describes two numerical methods for calculating characteristic parameters of multiconductor transmission lines. Both methods are based on the quasi-TEM assumption. The first method comprises the transformation of the field-describing differential equation into an integral equation, which is then solved numerically by applying the boundary element method (BEM). The advantage of this integral equation method is that the solution just has to be evaluated on the boundary of the considered domain. Hence, faster tools can be developed.rnIn the second part of this paper a method will be presented which is based on the iterative solution of a mixed boundary-value problem. In the first step of each iteration, a charge density is computed from suitably chosen starting values of the potential on the dielectric interface of the configuration. In the second step, the starting potential values for the next iteration are computed from a corrected charge density. The procedure terminates if the charge density on the dielectric interfaces does not exceed a fixed limit.rnFor validation, the line parameters calculated with both the methods are compared.