Noise coupling to signal trace and via from power/ground simultaneous switching noise in high speed double data rates memory module

We suggested the model to demonstrate simultaneous switching noise (SSN) coupling to signal and verified experimentally. There are two coupling mechanisms; one is the SSN coupling through the reference changing via, and the other is the SSN coupling through the signal trace. Through measurement and analysis, we confirmed that the worst SSN coupling occurs when strip lines have the signal via changing reference plane with SSN. Furthermore, we demonstrated that the power/ground noise coupling to the signal is reduced by placing the reference changing via at the position where the power/ground cavity impedance is low, or by adjusting the line length between two reference changing vias.