Jason Miller, Staff Engineer, Sun Microsystems
Gustavo Blando, Staff Engineer, Sun Microsystems
Istvan Novak, Senior Staff Engineer, Sun Microsystems

As board designs get denser, signal traces are often forced to route in proximity to board plane cutouts. Along the length of the trace, the trace may periodically encounter a cutout due to connector pin fields, via transitions, etc. In this talk, we examine the impact of periodic layer-to-layer coupling on far-end and near-end crosstalk. The coupling is found to increase the NEXT and FEXT and introduce periodic peaks in the NEXT profile. Realistic thermal relief patterns and antipads extracted from board designs are simulated. Time domain simulations will show the impact of this coupling on the voltage margin. Measurement results will also be presented.