Factors Affecting Near-End Crosstalk (NEXT) in High Speed Serial Links

In this paper, factors affecting near-end crosstalk (NEXT) in high speed serial links are discussed. When designing stripline transmission lines, care should be taken to tune parameters such as dielectric thickness of core and prepreg, intra-pair spacing and pair-to-pair spacing to minimize crosstalk. A less optimal design would result in higher crosstalk and may force designers to increase layer count in printed circuit boards (PCB) to reduce crosstalk. In this paper, by comparing eye-height differences between high speed channels with and without NEXT, the sensitivity of different transmission line parameters to NEXT is analyzed.