Modeling and analysis of coupling in gapped ground plane

This paper describes the mathematical modeling of the gapped ground plane structure used for suppressing the simultaneous switching noise (SSN) or ground bounce noise (GBN) in high speed printed circuit boards. The coupling coefficient for the gapped ground plane with a slot or split with feed line was analyzed using Ansoft HFSS (high frequency structure simulator) package and it was verified by measurement. Mathematically the power plane with slot or split was modeled and the coupling coefficient (S12) at the gapped ground plane was analyzed using a fast algorithm based on a full cavity-mode resonator model and the segmentation method. Inductance and capacitance model was used to account for the field coupling along the slot and the split, respectively. The effectiveness of the segmentation method and the inductance-capacitance model for the gapped structure has been demonstrated by good agreement between the simulated, measured and calculated results.