Items Tagged with 'coupling'

In this article, it is demonstrated that intra-pair skew cannot be properly defined on a screened single pair, as the signal launched in a single wire does not propagate as such along the pair due to inter-wire coupling.

Crosstalk problems here to stay as long as interconnects are designed as the open waveguiding systems. Thus, understanding and proper quantification of the crosstalk and mitigation of the consequences are important. This article outlines multiple possible ways to quantify the crosstalk: coupling coefficients, frequency domain metrics, time-domain analysis of crosstalk, and a modern statistical approach. 

Crosstalk in PCB and packaging interconnects is arguably one of the most complicated phenomena that may cause signal degradation. Crosstalk effects can be treated statistically as a deterministic jitter with a bounded distribution, but the distribution is usually not known. A direct analysis of a worst-case crosstalk scenario may lead to a system overdesign. Neglecting it in design may cause a system failure that is difficult to find and fix later in a design process. Distortions caused by crosstalk cannot be corrected by signal conditioning techniques at a receiver side. It is very important to understand the sources of crosstalk, how to quantify it and how to mitigate it efficiently, as Yuriy Shlepnev demonstrates in this installation of the "How Interconnects Work" series.

Successfully designing a PCB with more than one impedance while maintaining a manufacturable and economical product can be a difficult challenge. By examining the histories and uses of various impedances, Lee Ritchey simplifies the process and discusses the ideal impedance for PCB stackup design.