摘要
当今电气电子技术迅速发展，电器产品不断趋于电子化，电磁环境越来越复杂和恶化，印刷电路板（PCB）也随着日益高集成化，高频化。高频条件下，产生的脉冲谐波带来的电磁兼容性（EMC）问题直接影响电子产品的工作稳定性和可靠性。所以，在电气电子产品在完成功能设计的前提下，投入批量生产之前，分析和改善产品的电磁兼容性可以节约大量的成本和时间。
PCB中信号的频率越高，信号线就越容易产生电磁辐射，而其中的高频谐波是影响PCB性能的主要因素。本文采用分析电磁场的方法，通过使用一些商用软件对PCB进行仿真，来预测其中电磁干扰（EMI）可能带来的电磁兼容性问题。主要工作如下：
首先，分析电磁兼容的基本理论。说明了电磁干扰的原理、条件和种类，对抑制电磁干扰的方法进行总结。并分析了PCB中主要的电磁干扰，从而得出优化PCB的电磁兼容性的最佳研究方法。
其次，针对PCB中的电磁兼容性问题进行电磁场分析。用Ansoft Designer软件对已设计好的PCB进行分析，得到PCB的电流图和EM近场图，根据结果分析优化PCB方案。
最后，对PCB进行优化设计。通过改进PCB布线和元件布局，来提高PCB的电磁兼容性。对结果进行验证，验证成功后总结全文并概括研究成果。
关键词：PCB；电磁兼容；高频干扰；Ansoft Designer
Abstract
Today electrical and electronics technology is developing rapidly, appliances products tend to be electronic constantly, and Electromagnetic environment is more and more complex and deterioration, so that the PCB (Printed Circuit Board) becomes high integration increasingly. Under the condition of high-frequency, the problem of the EMC (Electromagnetic Compatibility) along with the pulse harmonic affect the stability and reliability of the electronic products directly. On the premise that the electrical and electronics products are completely designed, analysis and improve the EMC of the products before mass production will save plenty of cost and time.
The higher the signal frequency in the PCB is, the easier it is to produce electromagnetic radiation,and the high-frequency harmonics are the main factors influencing the performance of PCB. This article adopts the method of analysis of electromagnetic field, by using some commercial software, through the simulation on PCB to predict the possible EMC problems leaded to by EMI (Electromagnetic Interference). The main work is as follows:
First of all, the basic theory of EMC is discussed. The principle, conditions and types of electromagnetic interference are explained, and the methods to restrain EMI are also summarize. Then the main EMI in the PCB is analyzed to obtain the best method of optimizing the EMC of PCB.
Secondly, in view of the problem of EMC in PCB the electromagnetic field is analyzed. The software Ansoft Designer is adopted to analyze the designed PCB, so that the current figure and EM near field figure can be got, for obtaining the methods to optimize PCB.
Finally, the optimization of PCB is completed. By improving the wiring and component layout of PCB, the EMC of PCB is improved. After the result is successfully validated, the full text and the research results are summarized.
Key words: PCB; EMC; High-frequency interference; Ansoft Designer
目录
第一章 绪论
1.1 论文研究背景··············
1.2 PCB电磁兼容研究的目的及意义····················
1.3 国内外研究状况·······················
1.3.1 国外研究状况···············
1.3.2 国内研究状况····················
1.4 本文的主要研究工作及结构安排·················
1.4.1 研究设想······················
1.4.2 研究方法····················
1.4.3 结构安排··················
第二章 电磁兼容基本原理
2.1 电磁兼容概述
2.1.1 电磁兼容基本概念
2.1.2 电磁兼容常用术语解释
2.1.3 电磁兼容设计
2.2 电磁干扰
2.2.1 电磁干扰性质
2.2.2 电磁干扰三要素
2.2.3 电磁干扰分类
2.3 电磁干扰耦合途径
2.3.1 传导耦合
2.3.2 辐射耦合
2.4 电磁兼容控制技术
2.4.1 主要技术
2.4.2 其它技术
2.5 电磁兼容预测
2.6 本章小结
第三章 PCB中的电磁干扰与电磁兼容设计
3.1 PCB设计概述
3.1.1 PCB的类型
3.1.2 PCB的组成
3.1.3 PCB的设计
3.2 PCB中主要的电磁干扰
3.2.1 传输线理论
3.2.2 传导干扰
3.2.3 辐射干扰
3.3 PCB的设计自由度与抗干扰分析
3.4 PCB设计的基本原则
3.4.1 布局
3.4.2 布线
3.5 PCB的电磁兼容分析方案
3.6 本章小结
第四章 PCB电磁兼容性的仿真分析与优化
4.1 仿真软件介绍
4.1.1 Altium Designer
4.1.2 Ansoft Designer
4.2 PCB仿真步骤
4.3 PCB仿真及优化过程
4.3.1原理图的设计与输入
4.3.2 PCB的生成
4.3.3 PCB的仿真
4.3.4 PCB的优化
4.4 仿真结果分析
4.5 本章小结
总结与展望
参考文献
致谢
