传输线网络是现代电子设备内的重要组成部分和电子设备电磁场耦合的关键路径。计算复杂非均匀传输线网络中关键节点电磁耦合量，是评估电子系统复杂电磁环境易损性的重要环节。本文针对传输线网络中复杂线型、非理想传输结构、非匹配负载等因素引入的系统复杂性，以及不规则腔体内部存在的波混沌电磁环境引入的统计特性，基于克朗方法展开研究。克朗方法是一种基于网络张量分析和元胞拓扑的物理相互作用建模理论，对系统中相互作用具备较强的表征能力，在电磁耦合作用描述和耦合量计算中有独特的潜力。本文就复杂传输线网络的场线耦合克朗方法计算模型关键技术进行研究，并结合随机耦合模型实现了传输线端口响应的统计预测，最后对电离辐射下节点易损性分析做了初步探索。本文的主要成果如下：1）针对场线耦合的确定性计算场景，基于克朗-布朗宁传输线模型，推导建立了双端口场线耦合的频域计算宏模型。并将模型拓展至理想连接的传输线网络，以及考虑了非理想结构寄生效应的传输线网络。该模型的有效性通过电路、全波仿真和TEM小室电磁辐射实验得到验证。模型通过编程建立矩阵并求解，无需借助任何电路仿真软件即可自主实现计算功能。2）基于编织屏蔽层的转移特性，以及相邻导线的近场耦合现象的物理模型，在元胞拓扑理论下完成了数学模型的建立。将场线耦合模型拓展至屏蔽同轴线缆、非平衡差分耦合线、多导体传输线等复杂线型。拓展模型的有效性及计算效率与商用软件及流行算法进行了比较分析，模型的求解空间维度更低，在存储效率、计算效率均有优势。3）依据统计电磁学中的随机平面波假设，计算不同耦合结构在随机平面波入射下的平均吸收截面，结合随机耦合模型实现了波混沌环境内跨耦合对象的响应统计预测；通过实验验证了模型预测的有效性。4）利用克朗方法计算PCB微带线在电离辐射影响下的端口响应变化；并以模数转化芯片为典型效应物开展了器件失效阈值实验研究，通过威布尔分布对累积了不同剂量的小样本进行电磁失效概率阈值拟合。从传输线电磁响应和效应阈值两方面分析了复合辐射环境下的传输线节点的电磁易损性。初步探索了传输线网络和节点器件都存在累积退化情况下的节点概率阈值的确定方法。
Transmission-lines （TLs） networks are an important part of modern electronic equipment and the critical path of electromagnetic （EM） field coupling. The coupling calculation of key nodes in TLs networks composed of different types of TLs is critical for the susceptibility evaluation of electronic systems against complex EM environments. This work is based on Kron’s method and focuses on the system complexity introduced by the complex TLs, the parasitic effect of special structure, unmatched load, and other non-ideal factors in the TLs network, as well as the uncertainty caused by the wave-chaotic EM environment inside an irregular cavity.Kron’s method is a modeling theory of the physical interaction process based on tensorial analysis of network and cellular topology, which has an advantage in characterizing interactions and potential in the description of electromagnetic coupling and the calculation of coupling quantities. In this work, the calculation model of the field-lines coupling is studied using Kron’s method. The random coupling model is combined to realize the statistics response prediction of TLs. The susceptibility analysis of the key node under the composed radiation environment is explored in the end. The main researches of this thesis are as follows:1） For the deterministic calculation scenario of field-line coupling, based on the Kron-Branin TL model, the frequency-domain calculation model of the two-port field-line coupling is deduced and established. This model is extended to the ideal network and the one considering the existence of non-ideal structural parasitics parameters. The validity of the model is verified by circuit and full-wave software and experiments.2） Based on the physical model of the transfer characteristics of the braided shielding layer, and the near-field coupling phenomenon of adjacent wires, the mathematical model is established under Kron’s formalism. The field-line coupling KB model is extended to complex line types such as shielded coaxial cables, unbalanced differentially-pair, and multi-conductor TLs. The effectiveness and computational efficiency of the extended model are compared with commercial software and popular algorithms. The proposed model has advantages in solution space dimension and computation efficiency.3） According to the random plane wave assumption in statistical electromagnetism, the average absorption cross-section of different coupling objects under random plane wave incidence is calculated. Based on that the statistical prediction of the response across objects in the wave-chaotic environment is realized by combining the random coupling model. The model prediction is verified by experiments.4） The port response of the PCB microstrips under the influence of total ionizing dose （TID） is calculated using Kron’ method. The experimental study on the failure threshold of EM radiation and TID is carried out with ADC chips as a typical device under test. Through Weibull distribution, the electromagnetic failure probability thresholds are fitted with small samples. The electromagnetic susceptibility of TLs nodes in the compound radiation environment is analyzed from the aspects of TLs EM response and effect threshold. The method of determining the node probability threshold in the case of cumulative degradation of both the TLs network and devices is preliminarily explored.
