Kun Zhang, Engineer, Signal Integrity Group, Huawei Technologies
Zhen Mu, Silicon-Package-Board Division, Cadence Design Systems
Qingshan Quan, Signal-Integrity Group, Huawei Technologies
Xiangzhong Jiang, Signal-Integrity Group, Huawei Technologies

As signal speed transferred between chips and boards through packages goes up, it becomes more and more difficult for electronic products to pass EMI standard before going into market. As the most radiate component, printed circuit boards (PCB) need great attention for eliminating the causes that may fail EMI tests. Power/ground noise is one important radiation source on PCBs. This paper discusses the relationship between EMI and PI in high speed PCB design. It proposes and investigates the design methods to suppress power ground noise by utilizing different decoupling techniques. Evaluation boards are designed and manufactured to verify the methods. EMI in far field measurements, power plane characteristics, and power/ground noise are measured and correlated with simulation results. From the results of this study, the paper concludes that good power delivery strategy is another effective way in resolving EMI problems in high speed PCB designs.