Based on quality, relevance, impact, and originality, Syed’s paper “On the Minimization of PCB Differential Pair Skew or Its Effect” has been chosen as a finalist for a DesignCon 2019 Best Paper Award. Congratulations!


Syed Bokhari of Fidus is set to speak at DesignCon 2019 at the Santa Clara Convention Center on January 30, 2019.

Description: This paper presents two new methods for dealing with skew. Fiber-weave effect is minimized using a non-uniform differential pair. It consists of a hybrid combination of edge-coupled and broadside-coupled differential geometries. Traces are routed as “complementary twisted pairs”. Skew results in fading at a precise frequency and its multiples. It is discovered that the effect of skew can be reduced by using multiple strongly coupled elements. An exact analytical solution is derived for the differential insertion loss of a link comprising two tightly coupled sections. Numerical results are validated using 3D EM field solvers.

Takeaway: Why is differential pair skew so important? Because it causes fading! One can either “cure” the disease, or its symptoms. The disease is predominantly caused by a non-uniformity in the substrate material. Here we show that it, or, its symptoms can be cured by using non-uniform transmission lines.

The three-day conference will consist of more than 100 technical sessions spanning 15 tracks. More information about this event is available here.

Syed Bokhari
Technical Manager of SI and EMC
Fidus Systems Inc.