Semitopological Expansion for Link Decomposition Analysis

Abstract

Link decomposition is useful for assessing the contribution of each component to a link's overall signal integrity metrics, aiding engineers in prioritizing components for design optimization or failure analysis. This article presents a new approach for decomposition analysis based on semitopological expansion. Compared with perturbation-based decomposition methods, semitopological expansion proves suitable for decomposing not only insertion loss and crosstalk but also return loss, yielding results with clearer physical significance. Compared with another approach relying on Mason's rule, semitopological expansion exhibits lower computational complexity, rendering it more suitable for handling complex links in practical applications. These advantages are demonstrated through two examples: the decomposition of return loss for a dummy link, and the decomposition of insertion loss and crosstalk for a memory link. The article offers a detailed exposition of the decomposition procedure and demonstrates how the results can be interpreted to identify components critical to the link's signal integrity.