一种抑制同步开关噪声的新型蜂窝状电磁带隙结构

为了解决印刷电路板(printed circuit board,PCB)上高速电路中由于同步开关噪声(simultaneous switching noise,SSN)所引起的信号完整性问题,设计了一种新型蜂窝状电磁带隙结构(cellular electromagnetic band gap structure,CE-EBG),把传统的四边形周期单元改进为六边形,抑制同步开关噪声。利用HFSS软件对CE-EBG进行了建模和阻带特性的仿真。仿真结果表明,当抑制深度为-30 d B时,抑制带宽为3.75 GHz,相对带宽为132%,其中上限截止频率为4.7 GHz,下限截止频率为0.95 GHz。和传统的四边形EBG结构相比,其相对带宽增加了15%。在仿真基础上采用PCB工艺制作了CE-EBG结构实物,实测结果与仿真结果良好吻合。

A new cellular EBG structure for restrain simultaneous switching noise

In order to solve the signal integrity issue caused by the simultaneous switching noise (SSN) in high speed circuits of PCB, a novel planar electromagnetic band-gap (EBG) of cellular structure (CE-EBG),which brought the improvement for the periodical unit from conventional square-shaped to hexagon one, was designed to suppress the SSN. The structure and the stop-band characteristics of CC-EBG was modeled and simulated by using the electromagnetic simulation software HFSS. The simulation results show that, when the inhibition depth is -30dB, the inhibiting-bandwidth is 3.75GHz and the relative bandwidth is 132%, in which the upper cut-off and the lower cut-off frequencies of the new EBG are 4.7GHz and 0.95GHz respectively. Compared with the traditional square-shaped EBG, the relative bandwidth of CE-EBG increases 15%.On the basis of simulation, the realistic CE-EBG structure was fabricated with PCB process. The measurement results are well consistent with the simulation ones.