复杂强电磁环境下系统辐射敏感度测试方法

系统地介绍了复杂强电磁辐射环境下系统级装备辐射敏感度测试的开阔场辐照法、低电场扫描法、混响室和模拟器法.分析了每种方法的原理、特点及适用范围:开阔场辐照法实现的技术难度较小,但对硬件要求高且容易受到外界环境场干扰;低电场扫描法技术上容易实现,对硬件要求低,但需要获取辐射场与线束电流的递推关系;(混响室可以用较小的功放产生较强的电磁场;)模拟器法可以产生场强极高的辐射环境,且具有试验空间大,场均匀性好等优点,高压脉冲源的研制、辐射天线的设计是该方法需要解决的关键技术.     

用频设备内部线缆辐照响应特性研究

在用频设备内部大量存在着连接各子系统及外部系统的线缆.在外部电磁干扰环境中,其电磁能量可能穿透设备壳体耦合到设备内部,从而在设备内部的连接线缆上产生耦合电压致使设备工作性能受损.针对这一问题,文中结合时域有限差分法仿真计算,对机箱外壳及内部环境简要建模后,在箱体中设置单线、双绞线以及同轴线,并在机箱外部设置强电磁脉冲以...     

指挥通信车强电磁脉冲效应仿真分析

强电磁脉冲攻击对指挥通信车系统带来重大安全威胁。针对指挥通信车在高空核电磁脉冲(High Altitude Nuclear Electromagnetic Pulse,HEMP)下的电磁耦合问题,通过数值计算研究车辆结构、线缆和天线的电磁耦合响应,实现指挥通信车电磁脉冲效应的量化分析。仿真结果表明,电磁脉冲通过各种途径耦合到指挥通信车的瞬时脉冲信号足以造成电子设备出现干扰甚至损毁,导致执行任务失败。研究结果为指挥通信车系统的电磁脉冲防护设计奠定了基础。     

强电磁场环境中电磁防护的几点建议

信息系统设备工作在强电磁场环境中会受到很严重的损坏,对信息和通讯设备在强电磁脉冲环境中受到危害程度进行了探究。实验证明,计算机在强电脉冲环境中会受到很大的影响,计算机的功能会受到抑制。选用适当的电磁防护措施可以有效的减少强电磁场对信息通讯设备的影响。本文介绍了强电磁场环境和有这种类型环境出现的原因,列举出了强电磁场环境对计算机的危害,并且对强电磁脉冲环境下的防护措施提出了几点建议。     

高功率激光装置同轴线缆电磁脉冲耦合仿真

高功率激光装置开展实验会产生强烈的电磁脉冲辐射。电缆端口是电磁干扰耦合的重要途径。针对高功率激光装置上广泛使用的同轴线缆开展电磁脉冲耦合问题仿真研究,建立同轴线缆的电磁脉冲耦合仿真模型,研究不同入射方向、不同长度同轴线缆电磁脉冲耦合的感应电压。仿真结果显示,同轴线缆部署方向以及长度对电磁脉冲耦合具有显著的影响。本文对装置靶场线缆选型、线缆铺设以及诊断仪器电磁屏蔽设计有着参考价值。     

雷达电磁环境仿真分析

为提高雷达电子战电磁环境模拟逼真度,对雷达信号特征进行了分析,并用全软件的方法进行仿真模拟,将仿真出的结果与实际数据进行对比分析,为电磁环境仿真模拟的改进提出了参考意见。     

基于HLA复杂电磁环境下的对抗仿真模拟系统

建立一个基于HLA复杂电磁环境下的红蓝对抗作战行动的仿真模拟系统,对于更好地认知复杂电磁环境对作战行动的影响,检验战法和作战行动方案的合理性,有很大帮助。首先对系统的需求和功能进行了分析,然后研究了系统的体系结构,最后介绍了系统的仿真流程,体现了它的实用价值。     

某型车载电台强电磁脉冲环境效应仿真和试验

为检验某型车载通信超短波电台在高空核电磁脉冲环境下的生存能力,对该型电台建立全尺寸模型,进行了电磁脉冲耦合仿真分析,对比了该电台鞭状天线的前门耦合以及各互连线缆的后门场线耦合电流量级,得到前门耦合大于后门耦合的结论.结合仿真结果,对电台的强电磁脉冲环境适应性试验方法进行了设计,并采用威胁级辐照方法,采用垂直极化的电磁脉...     

防空武器系统复杂电磁环境效应的特征分析及仿真

防空武器系统面临的攻防对抗环境是由敌我双方的电子对抗装备综合产生的,从复杂战场环境的构成要素入手,着重分析了复杂电磁环境对防空武器系统的作用机理和系统效应,通过计算机仿真实例给出了一个典型防空作战电磁环境的态势显示,仿真结果将有助于深入分析影响雷达制导系统的复杂电磁环境构成要素,提出客观、准确的雷达制导系统性能评估准则和方法.     

Protective coatings of electronics under harsh thermal shock

Industrial electronics devices commonly encounter harsh environmental conditions during their operational lifetime. To protect the electronics from conditions like humidity and contaminants, protective moulding and coating materials can be used. However, the behaviour of materials in harsh environments and their effect on the reliability of electronics in industrial products has been studied only very little. Moreover, the changes in the parameters of several commonly used materials under various conditions remain largely unknown. In this paper the effect of the protective coating and moulding materials on product level reliability of an electronics device was studied under thermal shock test. In addition, the change in the mechanical properties of the materials under test conditions was studied. The conditions of the test used were relatively harsh with extreme temperatures of −40 °C and +125 °C. The samples used in the study were commercial electronics devices designed for use in harsh conditions. The protective materials studied included silicone based conformal coating, polyurethane based moulding material, and silicone based moulding material. Moreover, a comparison test with no protective materials was conducted. The results showed that conformal coating and polyurethane based moulding material markedly decreased the times to failures of the devices. On the other hand, silicone based moulding seemed to slightly improve the reliability of the devices.     

计算机线缆的电磁信息泄漏智能分析方法

计算机系统中的各型线缆会通过电磁传导发射泄漏内部信息,导致信息安全问题. 为了分析来自计算机线缆的电磁信息泄漏,提出了基于深度学习的智能分析方法. 设计一维卷积神经网络算法,对电磁泄漏信号进行深层的特征提取与学习,从泄漏的电磁信号中智能识别泄漏源的线缆类型,进而分析其中泄漏的视频信息. 实测结果表明,本文提出的方法,在未知目标信号特征的情况下,能够有效识别电磁信息的泄漏源与泄漏信息,为计算机线缆提供了一种电磁信息泄漏的智能分析手段.     

Joint reliability of various Pb-free solders under harsh vibration conditions for automotive electronics

These days, realization of technology for automotive electronics is important for convenience and safety in automobile industries. Although technology development is continuously progressing, various problems associated with the reliability of automotive electronics have arisen. In this study, combined vibration tests were performed to determine the reliability of various solders under harsh environments: Sn-3.0Ag-0.5Cu (SAC305), Sn0.7Cu and Sn-0.5Cu-0.01Al-0.005Si-0.008Ge (SnCuAl(Si)) solder (in wt%). The Pb-free solder balls were used on electroplating nickel finished Cu pads of a fine ball grid array (FBGA) package. The BGA packages mounted with solder balls were set up on electroless nickel-immersion gold (ENIG) finished Cu pads of a daisy-chained printed circuit board (PCB). The combined random vibration test was performed under 2.5 G_rms in the range of 400 to 2000 Hz in the temperature range of −45 to 125 °C and was continued until 500 cycles. The reliability of the solder joint was determined by measuring the electrical resistance using a multi-meter. The resistance gradually increased and finally approached infinity. In addition, the IMC thicknesses increased during the combined random vibration test, which affected the fracture behavior. To determine the reliability of the solders, the number of failures of solders and the crack morphology and propagation in each solder were evaluated. Among the three solders, the SnCuAl(Si) solder demonstrated the best reliability.     

A systematic coupled approach for electromagnetic susceptibility analysis of a shielded device with multilayer circuitry

This paper presents a systematic coupled approach for electromagnetic susceptibility (EMS) analysis of a shielded electronic device in the presence of an ambient electromagnetic interference (EMI). A full-wave electromagnetic modeling technique coupled with a circuit-based method is developed for the overall EMS performance analysis. The mixed-potential electric field integral equation (MPIE) is formulated via the method of moments to model the electromagnetic properties of an arbitrary structure consisting of wires and surfaces with any applied excitation. With numerical analysis, the effect of an ambient electromagnetic noise is characterized, and an equivalent circuit model is extracted for further analysis of EMI to internal high-speed sensitive circuits. Numerous examinations exhibit that this systematic coupled approach is a computationally efficient method to address the EMS problems at system level, in which the external EMI effects are fully considered and the circuit-based simulator is also exploited.     

Electrothermal model of the electromagnetic irradiation of semiconductor structures

A numerical electrothermal model of the action of electromagnetic radiation (EMR) pulses on discrete electromagnetic devices and IC elements is presented. A silicon high-frequency diode with the Schottky barrier is used as an example in the numerical calculation of electro- and thermophysical processes at various energy and power parameters of the EMR pulse.     

数字信号控制器电磁敏感度的环境温度影响研究

针对典型数字信号控制器(Digital Signal Controller, DSC)的电磁兼容问题, 提出了电磁特性与温度特性相结合的分析方法, 研究了环境温度对其传导电磁敏感度的影响.结合电磁敏感度行为级模型结构, 分析了电磁干扰的作用机制, 导出了DSC中金属-氧化物-半导体(Metal-Oxide-Semiconductor, MOS)器件阈值电压和迁移率随环境温度的变化关系;利用直接功率注入与环境温度联合控制技术, 从实验和仿真两个方面分析了模型各部分特征参数在不同温度下的变化, 揭示了电磁敏感度在不同环境温度下变化的内在因素, 并测试了不同温度下典型DSC的电磁敏感度阈值.结果表明, DSC敏感度行为单元中MOS器件阈值电压和迁移率在不同温度下的变化, 会造成其电磁敏感度随环境温度产生显著漂移.     

大功率电子设备节能降耗方法分析

随着人们生活与工业生产对于用电量的需求越来越大,使得电网中的总电流不断增加,这样一来节能降耗就成为了关系国民经济安全、国际市场竞争力以及资源环境保护等社会经济可持续发展的重大问题。尤其对于我国而言,电力缺口很大,节约能源、降低污染、提高能效,坚持可持续发展道路是今后电力企业发展的主要路线。因此,本文对大功率电子设备节能降耗的方法进行浅析。     

Characterisation of electromagnetic susceptibility of integrated circuits using near-field scan

A susceptibility characterisation test for integrated circuits using a miniature magnetic near-field probe is described. The method is efficient up to a frequency of 6 GHz and maps immunity to radiated fields