A Novel Causal Method to Blend the DC and AC Solution Over the Entire Frequency Band

This paper proposes a novel DC correction method to correct the inaccurate low-frequency S-parameters obtained from an electromagnetic simulator so that S-parameters have an exact DC-point and the electromagnetic transient analysis using the S-parameters is accurate and reliable in signal integrity, power integrity, and power electronics applications. The new method can correct the low-frequency region of S-parameters to the given reference DC-point by adding a causal and rational correction function over the entire frequency band. The method ensures that the corrected S-parameters have a precise DC-point while preserving the original AC solution’s causality, passivity, and high-frequency accuracy.