屏蔽层对电缆寄生参数的影响分析

电缆作为连接各种电子设备必不可少的元件,是电磁兼容设计的重点问题之一,大部分电磁干扰敏感问题、电磁干扰发射问题、信号串扰问题都是电缆产生的。针对电缆是否应用屏蔽层的电磁干扰问题进行对比分析,通过运用Q3D软件对电缆的寄生参数进行提取并得到其场分布图,建立电缆的等效电路模型,使用6500B阻抗分析仪对于屏蔽电缆和非屏蔽电缆的寄生参数进行测量验证,分析了屏蔽电缆的接地原因。研究结果表明:屏蔽电缆的寄生参数有所增加,但是其对辐射干扰有明显的抑制作用。

The comparative analysis about cable shielding quality

As an absolutely necessary components to connect all kinds of electronic equipment, cable is one of the key problems of electromagnetic compatibility design, most problems are produced by the cables such as being sensitive to electromagnetic interference, electromagnetic interference emission, signal crosstalk.This paper is aimed at giving the comparative analysis of whether shielding layer should exist in cables or not for electromagnetic interference problem, this paper is aimed at giving the comparative analysis of whether shielding layer should exist in cables or not for electromagnetic interference problem. By using Q3D software to extract the parasitic parameters of the cable and geting the field distribution, establishing the equivalent circuit model of the cable,then using 6500B impedance analyzer to do the measuring and verifying the parasitic parameters of shielded cable and nonmaskable cables,the reason of the shielded cable grounding has been analyzed. The result proves that the inhibitory effect on radiated interference is obvious,though the parasitic parameters of shielded cable increases.