Efficient equivalent circuit representation of electromagnetic bandgap structures

A simple and effective method to attenuate the propagation of switching noise within a power delivery network (PDN) on PCB-level is to use an electromagnetic band-gap structure (EBG). To determine the limit frequencies of the band-gap, an accurate model of the structure is necessary. This paper exploits the fact, that the patches of the EBG are electrically small at the frequency range below the band-gap. This allows the accurate representation of the structure by a coupled inductive network model. Especially for simple patch shapes compact closed-form expressions can be derived for each network element. As an example the suggested modeling approach is demonstrated for a symmetric EBG-shape with square patches. The comparison with 3D-full-wave field simulation and measurements shows a very good agreement.