The package and the printed circuit baseplate (PCB) in the high-speed digital system above, the noise insulation which is improved

摘要

Improved noise isolation for high-speed digital systems on packages and printed circuit boards is provided by the use of mixed alternating impedance electromagnetic bandgap (AI-EBG) structures and a power island configured to provide ultimate noise isolation. A power island is surrounded by a plurality of mixed AI-EBG structures to provide a power distribution network. In this structure, the gap around the power island provides excellent isolation from DC to the first cavity resonant frequency which is determined by the size of the structure and dielectric material. One AI-EBG structure provides excellent isolation from the first cavity resonant frequency of around 1.5 GHz to 5 GHz. The other AI-EBG structure provides excellent noise isolation from 5 GHz to 10 GHz. Through use of this novel configuration of AI-EBG structures, a combination effect of the hybrid AI-EBG structure provides excellent isolation far in excess of 10 GHz. The AI-EBG structure is a metallic-dielectric EBG structure that comprises two metal layers separated by a thin dielectric material (similar to power/ground planes in packages and PCBs). However, in the AI-EBG structure, only one of the metal layers has a periodic pattern which is preferably a two-dimensional rectangular lattice with each element consisting of a metal patch with four connecting metal branches.