非均匀螺距的双绞线串扰统计特性分析

双绞线的螺距误差会直接影响其抗干扰水平，螺距误差的随机性会造成双绞线串扰预测的不确定性.通过双绞线制作原理的分析，利用制作参数可以较准确得到任意双绞线螺距误差的概率密度.采取等弧度离散法和广义多端口网络的概念，快速建立非均匀螺距双绞线的频域串扰模型，得到感性耦合和螺距误差的关系.基于螺距误差的概率密度函数，可以有效分析任意双绞线串扰的统计特性.仿真结果表明双绞线制作参数转轴角速度的均值和方差是影响双绞线感性耦合大小的关键因素，在双绞线制作过程中必须予以考虑，以保证双绞线的抗干扰能力. 

Statistical analysis for crosstalk of twisted-wire pairs with non-uniform pitch

The pitch error of random twisted wire pair (TWP) could directly impact the immunity levels of TWP. The randomness of pitch error would cause the uncertainty of crosstalk prediction of TWP. According to the analysis of the TWP production principle, the probability density of the pitch error of TWP was accurately obtained by the production parameters. The crosstalk model of the TWP with non-uniform pitch was rapidly presented by the equal radian discrete method and concept of generalized multi-port network, likewise, the relationship between the inductive coupling and pitch error was obtained. The statistical properties of crosstalk in random TWP could be analyzed effectively based on the probability density function of pitch error. The simulation analysis further validates that the mean and variance of shafts' angular velocity are the key factors of affecting the inductive coupling of random TWP. For the TWP production, the mean and variance of shafts' angular velocity must be taken into account carefully to ensure the immunity levels of TWP.