What is the minimum unit cell size for an EBG structure in a PDN?
The answer is dependent on the type of EBG structure. Hybrid EBG structures can employ chip caps as part of the resonant vias, and this will dramatically lower the cutoff frequency, or the edge of the fundamental stopband, to well below 100 MHz. In fact, hybrid EBG structures with a 30 MHz cutoff and a inch period have been demonstrated in conventional FR4 printed circuit boards.
