Accuracy and performance of passive transmission line macromodels based on optimal matrix rational approximations

This paper describes the implementation of a macromodeling technique for lossy transmission lines with frequency-dependent data in the API framework of IBM's PowerSpice circuit solver. The technique is based on finding passive, low-pass, optimal matrix rational approximations of the line admittance matrix. This implementation is used to compare the accuracy and performance of these new passive transmission line macromodels with those of the generalized method of characteristics on the one hand and the matrix Pade approximation on the other.