Signal Integrity Enhanced EBG Structure With a Ground Reinforced Trace

Abstract

In general, a conventional electromagnetic bandgap (EBG) structure efficiently suppresses simultaneous switching noise (SSN) over a wide frequency range. However, it is difficult to apply the geometry to the design of a real printed circuit boards (PCBs) for high-speed digital circuits due to the degradation in the signal integrity performance. In this paper, a ground reinforced trace (GRT) is added to the EBG power plane to guarantee power integrity (PI) as well as signal integrity (SI) simultaneously. In addition, the definition of a noise suppression bandwidth in an EBG structure is derived for the purpose of analyzing the correlation between the GRT and the noise suppression bandwidth. This correlation is utilized to decide the location of the GRT to mitigate the degradation of the low-pass cutoff frequency. As a result, an excellent signal performance is achieved without any degradation of the noise suppression bandwidth in a conventional EBG structure.