On the coupling between the signal layers and the power-bus on multilayered PCBs

In this paper, lumped models are used to describe the effects of vias in multilayered PCBs. Possible effects of a via on a 4-layer PCB are explained and investigated: the coupling between the via and the power-bus, and the influence on the signal propagation at the via transition. In addition, a computation procedure using lumped models for PCBs with more than 4 layers is presented and some special effects on a via are explained. Finally, another possible coupling mechanism, the direct coupling of the waveguide modes from the power-bus into a stripline is investigated.