ABSTRACT

Numerical analysis of crosstalk between two traces in a printed circuit board is presented using the method of moments (MoM). In the high-frequency range, the attenuation constant is neglected in the theory for its very small values. The width of the trace is accurately determined for the trace impedance of 50 ohm from the charge distribution on the traces without using an approximated empirical formula. Line capacitances are determined from the total charge on the conductors and the line potentials. The coupling capacitance and inductance are determined from in-phase and out-of-phase excitations between the traces. Crosstalk interference is calculated from these coupling parameters. Results of crosstalk obtained from the above technique are verified by comparing with those obtained from four other methods: (1) Ansoft HFSS software tool, (2) even mode and odd mode analysis, (3) empirical formulae of parasitic elements, and (4) measurements using a vector network analyser. All the results agreed well. The results obtained by using the method of moment technique are more stable, reliable, and accurate among all the described different methods. This paper shows that the analytical method using MoM is a useful tool for predicting crosstalk interference in PCB without using expensive simulation software.

摘要

使用矩量法 (MoM) 对印刷电路板中两条迹线之间的串扰进行了数值分析。在高频范围内，衰减常数在理论上被忽略，因为它的值非常小。对于 50 欧姆的走线阻抗，可以根据走线上的电荷分布准确确定走线的宽度，而无需使用近似的经验公式。线路电容由导体上的总电荷和线路电位决定。耦合电容和电感由迹线之间的同相和异相激励确定。根据这些耦合参数计算串扰干扰。通过与其他四种方法获得的结果进行比较，验证了上述技术获得的串扰结果： (1) Ansoft HFSS 软件工具，(2) 偶模和奇模分析，(3) 寄生元件的经验公式，以及 (4) 使用矢量网络分析仪的测量。所有的结果都很好。在所有描述的不同方法中，使用矩量技术方法获得的结果更稳定、可靠和准确。本文表明，使用 MoM 的分析方法是一种有用的工具，可以在不使用昂贵的仿真软件的情况下预测 PCB 中的串扰干扰。