Crosstalk reduction in printed circuit boards using irregularly-spaced vias in a guard trace over a slotted ground plane

In a printed circuit board (PCB), a guard trace can be used to reduce crosstalk between adjacent traces. Regularly-spaced vias are generally used to connect the guard trace to the solid ground plane underneath it. However, when the ground plane is slotted or gapped, this approach may not be possible due to the openings. This paper proposes to solve this problem for slotted ground planes by using a small number of irregularly-spaced vias. It is shown by simulation that the proposed solution reduces both crosstalk and radiated emission.