Quality assurance of S-parameters and rational function models for transient simulations

S-parameters of electrical networks are often extracted using an electromagnetic (EM) simulator, and imported directly or after conversion to rational function models into a transient circuit simulator. However, there are several issues related to frequency-defined models that might prevent successful transient simulation. In this work, the requirements for S-parameter and rational function models in the frequency domain leading to successful transient simulations are studied in detail. Application examples of corrupted transient simulation results due to failure to meet these requirements are presented. This work also presents a quality assurance methodology to ensure that S-parameter and rational function models satisfy such necessary requirements. In particular, a new method is proposed to check the DC values of S-parameters obtained from EM simulation.