A Low-Frequency Accurate Cavity Model for Transient Analysis of Power-Ground Structures

With increased operating frequencies and circuit component density, signal and power integrity problems caused by voltage bounces have become more important for high-speed digital systems. This paper presents a systematic macromodeling of power-bus structures based on the cavity model: first, more accurate models are used to describe conductor and dielectric losses, thus improving accuracy at low frequencies; second, a rational model of the overall power/ground structure in the Laplace domain is presented, and third, the rational macromodel is used to identify the dominant poles, and a simplified SPICE-compatible equivalent circuit is synthesized by using only the selected poles. The numerical results confirm the correctness and effectiveness of the method.