基于低通滤波网络减小PCB上互连线间串扰方法的研究

针对印刷电路板(PCB) 上高速信号线与电源线间的串扰问题,提出了运用简洁的RC 低通滤波网络减小互连线间串扰的方法.在分析串扰抵消原理的基础上,对传输电源信号的互连线终端串接一阶RC 低通滤波电路网络,对来自于干扰线上的串扰信号进行滤波,从而减小串扰来保证电源信号的稳定;通过理论分析,给出滤波电路中 RC 取值的近似计算公式.仿真与实验结果表明,所设计的方法在频率低于660MHz 时,可使串扰减少10dB 以上;当频率范围为660M ～ 1. 22GHz 时,串扰减少6-10dB;当频率范围为1. 23G-3G 时,串扰减少2-6dB.本文提出的方法与传统通过使用物理结构减小串扰的方法相比,串扰减小的效果比较明显,且电路易于实现,成本较低.

Method Study Based on the Low Pass Filtering Network to Reduce Crosstalk between Interconnection Lines in PCB

In the paper aiming at the crosstalk between the power line and high speed signal line of printed circuit boards(PCB), a method using a simple RC low pass filtering circuit network is proposed to reduce the crosstalk between lines. On the basis of analyzing the crosstalk-cancellation principle, a RC low-pass filtering circuit network at the end of the power line is employed to filter the crosstalk signal produced by the high speed signal aggressor line. By filtering the crosstalk to reduce the far-end crosstalk signal on the victim line makes the power signal stable. Meanwhile, an approximate formula is presented for calculating the parameter value in this crosstalk filtering circuit. Simulated and experimental results show that the proposed method at the lower frequency band 660MHz can attenuate the crosstalk peak by more than 10 dB. When the frequency band from 660M to 1. 22GHz, attenuation of the crosstalk peak is about 6 ～ 10dB. peak is about 6 ～ 10dB. When the frequency band from 1. 23GM to 3GHz, attenuation of the crosstalk is about 2 ～ 6dB. As compared with the traditional methods using physical structure to reduce crosstalk, the proposed method is of a greatly-improved cancellation effect and the corresponding circuit is easy to realize with a low cost.