摘要当今社会正由工业化转向信息化,信息交流的重要性不言而喻,计算机技术、通信技术、网络技术的现代化推动了信息化社会的演进。在这些领域中普遍使用高密度、高频率、高速度的电路板,这些电路会产生很强的电磁干扰,为了保证电子设备的正常工作、减少相互之间的电磁骚扰、降低恶劣的电磁环境对人类及生态环境产生不利的影响,对电子产品的电磁兼容设计是现代电子设计不可忽视的问题。如不加处理将影响设备性能甚至无法正常工作。本设计将理论与实际相结合,一方面介绍了产生电磁兼容问题的基本原理,归纳了使用protel99在PCB设计阶段消除射频前端电路中电磁兼容性问题的具体措施;另一方面着手PCB的设计工作,以射频前端电路中的正交调制模块、低噪声放大器模块和混频器模块为例,设计了具有一定电磁兼容性的PCB图。中心思想是消除传输线效应,用合理的布局布线规避串扰,用阻抗匹配规避反射,配以合适的接地方式保证信号的完整性。9171
关键词 电磁兼容 射频 PCB
毕业设计说明书(论文)外文摘要
Title The EMC design of RF front-end circuit
Abstract
The modern society is shifting from industrialization to informatization,the importance of the exchange of information is apparently.The evolution of informatization is promoted by computer technology,modernization of communications technology and network technology.In these areas, the widespread use of high-density, high-frequency and high-speed circuit boards causes the EMC problem.In order to ensure the normal operation of electronic equipments and reduce the negative impact of harsh electromagnetic environment on human, the EMC design can not be ignored in the area of electronic design .If not deal with the EMC problem,devices can even not work.This paper combined theory with practice and described the basic principles of EMC.The measures to eliminate the EMC problems in the RF front-end circuit on the PCB design stage by use of protel99 is discussed in this paper.For example,this paper designed PCBplans of quadrature modulation module,LNA module and mixer module.
The central idea is eliminating transmission line effects.The crosstalk can be avoided by using a reasonable layout .Also,the reflection noise can be avoided by impedance matching. And an appropriate design of ground connection can ensure the integrity of the signal.
Keywords EMC RF front-end circuit PCB
目 次
1 绪论1
1.1 我国电磁兼容现状 1
1.2 本文研究的主要内容和成果 1
1.3 本文内容安排 2
2 系统介绍2
2.1 发射机2
2.1.1 发射机概述 2
2.1.2 发射机系统性能3
2.2 接收机3
2.2.1 接收机系统概述3
2.2.2 接收机系统性能4
3 电磁兼容(EMC)介绍及设计规则6
3.1 电磁兼容中常用定义6
3.1.1 电磁兼容6
3.1.2 电磁干扰6
3.1.3 电磁敏感度6
3.2 PCB中射频能量的产生与传输线概述6
3.2.1 PCB射频能量的产生6
3.2.2 传输线概述7
3.3 影响印制电路板级电磁兼容的因素9
3.3.1 布局不当10
3.3.2 布线不当10
3.3.3 器件边沿速率10
3.3.4 高频电流10
3.3.5 接地不当10
3.3.6 回路面积大10
3.3.7 射频和模拟电路的布局不当10
3.3.8 基材选择10
3.3.9 地电层绝缘沟槽分割不当11
3.3.10 导通孔的分布参数11
3.4 通用EMC设计规则11
3.4.1 元器件的选择11
3.4.2 印制电路板的布局12 射频前端电路PCB板电磁兼容性研究:http://www.youerw.com/tongxin/lunwen_7800.html