An educational tool for understanding reflections and crosstalk

Usually on a printed circuit board (PCB), the common signal integrity (SI) problems are generated by reflections and crosstalk. Nowadays, the high clock frequencies and communication throughput increases the chances of electromagnetic interference. In these conditions it is necessary to help the young students to understand how the two phenomena influence the propagation of signals. This task is not easy, as the two phenomena are related to electromagnetic field lines and depend on many physical (e.g. trace length, impedance) and electrical parameters (e.g. driver output impedance, rise/fall time). In order to facilitate the teaching process, a software tool in MatLab was developed. The MatLab environment allowed describing the two SI interferences from an analytical approach, based on simplified equations. Complex equations were also implemented, in order to accurately present the effects of the two perturbations after the basics are understood.