阶梯型缺陷地的超宽带共模抑制滤波器

Design of UWB Common-mode Suppression Filter Using Tapered Defected Ground Structure

提出了一种使用阶梯型缺陷地结构(DGS)对GHz差分信号进行共模抑制的超宽带滤波器。阶梯型DGS在高速差分信号中的应用很大的改进了共模噪声抑制和阻带宽度。在此基础上,构建出一个均匀分布和几个不均匀分布的方形周期DGS共模噪声抑制滤波器。通过适当设计周期结构的栅格大小构成多个不同位置的S21零点,使得通带的整体匹配良好,从而实现一个较宽的阻带。经过一系列的仿真,制作并测量了2个DGS电路。仿真结果显示共模抑制的阻带带宽大约15 GHz且衰减超过20 dB,验证了设计的正确性。

A novel ultra-wideband filter design for common-mode noise suppression of GHz differential signals is presented. The application of tapered periodic defected ground structure （ DGS） in high-speed differential signals greatly improves the common-mode noise suppression and the stop-band width. Based on this,a uniform square-patterned periodic DGS and several non-uniform square-patterned periodic DGSs are proposed for common-mode noise suppression filters. A proper design of the grid size of the periodic struc-tures makes multiple zero Scc21s of different positions to realize a wide stop-band. Through a series of simulations,two periodic DGS circuits are fabricated and measured. The results verify the design method by showing a large stop-band bandwidth of about 15 GHz over 20 dB in common-mode suppression.