Passive interconnect reduction algorithm for distributed/measured networks

This paper presents an efficient algorithm for the transient simulation of multiport distributed interconnect networks in the presence of nonlinear subcircuits. The proposed multilevel multipoint model-reduction algorithm combines the merits of recently proposed Krylov-space techniques and block complex frequency-hopping to generate compact time-domain macromodels. The method overcomes the difficulty of slower transient simulation caused by redundant poles in reduced-order models obtained by Krylov-space methods. Also, it provides an efficient means to translate Krylov-space-based reduced models of distributed/measured networks with frequency-dependent descriptions into time-domain macromodels. In addition, a strategy to preserve the passivity of macromodels during multilevel reduction is presented. An important advantage of the proposed algorithm is that it can directly handle distributed stamps such as transmission lines described by Telegrapher's equations, frequency-dependent parameters, full-wave, and measured subnetworks.