Differential mode to common mode conversion on differential signal vias due to asymmetric GND via configurations

This study investigates the impact of ground vias placed in close proximity to high speed differential signal vias and the resulting differential mode to common mode conversion. The work shows the influence of the distance between ground (GND) vias and differential signal (Diff. SIG.); the effect of the asymmetrical configuration of the GND vias; the impact of the dielectric thickness and the number of transitions between the planes.