A novel electromagnetic bandgap (EBG) structure for mixed-signal system applications

A novel electromagnetic bandgap (EBG) structure called alternating impedance EBG (AI-EBG) for isolation in mixed-signal systems is proposed. Currently, split planes are usually used for isolation in mixed-signal systems. However, split planes show a poor isolation at high frequencies due to electromagnetic coupling through a gap. This novel EBG structure shows excellent isolation by suppressing almost all possible electromagnetic modes in stopband frequencies. The S-parameter measurements show that this novel EBG structure could suppress noise coupling between RF/analog circuits and digital circuits, especially where a single common power supply is used. Mixed-signal system simulations with and without this novel EBG structure were performed to see improvement of isolation due to this novel EBG structure.