Crosstalk Impact of Periodic-Coupled Routing on Eye Opening of High-Speed Links in PCBs


Minimizing costs in printed circuit board layouts has led designers to use two signal layers between the reference planes, which introduce broadside coupling. Additionally, due to the fiber weave effect, designers route signal traces in a zig-zag fashion rather than in straight lines. This type of routing tends to be roughly periodic between the victim and the aggressor. The periodic-coupled routing creates periodic resonances in the near-end crosstalk and nulls in insertion loss (THRU) transfer functions as a consequence of Floquet modes. Due to the periodic resonances, the crosstalk is aggravated, which reduces the signal to crosstalk ratio. This study quantifies the effect of crosstalk due to periodic routing. In addition, design guidelines based on the angle of routing, length of period, and signaling speeds are formulated for designers using statistical bit error rate eye analysis.


Electrical and Computer Engineering

Research Center/Lab(s)

Center for High Performance Computing Research

Second Research Center/Lab

Electromagnetic Compatibility (EMC) Laboratory

Keywords and Phrases

Bit error rate; Crosstalk; Design; Printed circuits; High-speed links; Minimizing costs; Near end cross talks; Periodic routing; Printed circuit board layout; Reference plane; Signal to crosstalk ratios; Signal traces; Printed circuit boards; (BER); broadside coupling; Floquet mode; insertion loss (THRU); (NEXT); periodic routing

International Standard Serial Number (ISSN)


Document Type

Article - Journal

Document Version


File Type





© 2015 Institute of Electrical and Electronics Engineers (IEEE), All rights reserved.

Publication Date

01 Dec 2015