S-parameter based macro model of distributed-lumped networks using Pade approximation

A scattering-parameters (S-parameters) based macromodel of distributed-lumped networks is presented. The networks can include capacitive cutsets, inductive loops, RLC meshes, and lossy transmission lines. An efficient network reduction algorithm is developed to reduce the original network into a network containing one multiport component together with the sources and loads of interest. The S-parameters of the circuit components are approximated by Taylor series to simplify the reduction process. The Pade approximation is used to derive the macromodel. The macromodel is very flexible and the accuracy of the model can be controlled by adjusting the order of approximation. The experimental results indicate that the model can approach the accuracy of SPICE with one or two orders less computing time