摘要
共模噪声对信号完整性(SI)和电源完整性(PI)性能的影响日益严重,且随数据传输速度的不断提高而引起严重的电磁干扰(EMI)问题。在传统滤波方法逐渐失效甚至无法解决问题的情况下,研究人员基于人工材料的基础理论提出了缺陷地结构(DGS)的新型设计,其独特的电磁特性能够有效抑制高频共模噪声。文章通过对几种DGS共模滤波器的设计和研究,介绍和讨论了这种滤波技术的特点。为了有效分析其在工作频段的插入损耗,阐述了该类滤波器的基本原理和等效电路建模方法 ,并对该类滤波器的另一个重要特征——负群延迟(NGD)及其对SI和EMI的改善首次进行了探讨。
The common-mode noise deteriorates signal integrity(SI)and power integrity(PI)much more than ever before and induces critical electromagnetic interference(EMI)issues subsequently due to the ever increasing of the data transmission speed.While conventional filtering approaches become less efficient or even null to resolve the problems,a novel design termed defected ground structure(DGS)with its unique electromagnetic properties,is found to be able to mitigate the high frequency common-mode noise effectively.This kind of filter technology is introduced and discussed in the paper through the study of various common-mode filters.To analyze the insertion loss in the interested frequency range,the fundamental mechanism and equivalent circuit modeling of the filters are elucidated,another special but important characteristic of such filters,negative group delay,is also addressed for SI and EMI improvement at first time.
