Analysis of Simultaneous Switching Noise Coupling in Multilayer Power/Ground Planes With Segmentation Method and Cavity Model

An accurate power bus model is essential for predicting noise coupling in high-speed printed circuit board (PCB) and package designs. With a complex multilayer structure, the power bus is often modeled using numerical simulation methods. However, full-wave approaches are computationally inefficient, or even infeasible for extremely complicated geometries. Fortunately, the segmentation method makes it possible to combine different types of models together, and both simulation accuracy and efficiency can be obtained through this “divide-and-conquer” strategy. After segmentation, one of the fundamental blocks is a parallel plane pair. For this block, analytical expressions for the impedance (Z) matrix are available for a rectangular plane pair and some special triangular plane pairs. The combination of the cavity model with the segmentation technique has been known to be an efficient way to analyze irregularly shaped multilayer structures. In this paper, this approach is further extended to the general multilayer structures with overlapping planes. Noise-coupling mechanisms are then studied, and the two main coupling mechanisms, the plane edge coupling and the via coupling, are further characterized. Engineering implications on reducing noise coupling in a practical multilayer PCB are discussed through a series of simulation examples.