A Passivity Enforcement Scheme for Delay-Based Transmission Line Macromodels

This letter presents an algorithm for the enforcement of passivity in transmission-line macromodels based on the generalized method of characteristics. The algorithm is based on first-order perturbations of the solutions to a frequency-dependent eigenvalue problem. The theoretical formulation provides an extension of techniques that were available only for lumped models to the more general class of delay-based models.