Noise Isolation Modeling of Partial EBG Power Bus using Segmentation Method and Cavity Model in Multi-layer PCBs

In this paper, we present a new modeling approach based on a segmentation method for noise isolations of a power bus in which partial electromagnetic bandgap (EBG) structures are embedded. When the EBG structure is inserted partially in the power bus, the stopband characteristics such as the cut-off frequencies and the noise isolation level are different from those predicted by the models assuming infinite EBG cells. The proposed modeling approach enables to predict the noise coupling coefficient of the partial EBG power bus accurately in the stopband as well as the passband. In the proposed modeling, the partial EBG power bus is divided into three segments of the partial EBG structures and the different size rectangular power/ground planes. The partial EBG structure is further divided vertically and modeled as the transmission line networks with via structure and a rectangular plane cavity model. The proposed modeling approach based on the segmentation method has been validated by good agreement between the modeling result and the electromagnetic simulation result.