【作者】 曾志纯；

【导师】 李庆；

【作者基本信息】 武汉理工大学 ， 通信与信息系统， 2004， 硕士

【摘要】 随着人们对网络通信需求的不断提高，人们希望不论何时、何地、与何人都能够进行包括数据、语音、图像等任何内容的通信，并希望实现主机在网络中的漫游。为了提高工作效率和随时能够交换和处理信息，人们提出了移动计算机网络的概念。为了使无线网络系统不仅支持移动终端之间的通信，而且应允许无线设备接入有线网络，达到宽带通信和全球连接的目标，一个新的领域—无线局域网WLAN(Wireless Local Area Network)应运而生。随着WLAN的广泛应用，作为增加WLAN通信距离、增大WLAN覆盖范围的重要的高频部件——双向功放和天线的作用越来越重要。 本文以双向功放和天线在WLAN中的应用为线索，对双向功放在使用过程中出现的非线性失真问题和组网天线技术进行了理论研究和实验仿真。文章首先介绍了功放中的线性化技术——预失真技术和前馈技术。分析研究了预失真技术和前馈技术的原理、性能及其实现方法，并在深入研究两种技术的基础上，提出了集合两者优点于一体的自适应前馈预失真线性化系统方案。接着对典型WLAN功放进行了电路结构和性能的分析研究，并着重分析了功放电路中线性化技术的应用以及在线性化方面的改进，同时对功放相关的性能进行了测试。最后本文介绍了WLAN中的组网天线技术，分析了常见天线性能指标，对几种不同种类天线进行了性能分析与比较，并以某定向天线为例进行了结构和性能的分析研究。同时也研究了天线在WLAN中的应用技术。 由于WLAN的应用日益广泛，人们的需求迅速增长。本课题的研究成果对WLAN的覆盖面积，解决传输接收信号中等面临的问题，改善WLAN的通信性能具有重要的理论指导意义。更多还原

【Abstract】 With the increasing demand for network communication, people hope to have any form of communications whenever and wherever including data, voice and video with anyone, and to realize that host computers can roam in the network. People have put forward the concept of mobile computer network. To make wireless network system not only support the communication between mobile terminals, but also make wireless devices access to wired network to obtain the goal of broadband communication and global internetworking, a new field-Wireless Local Area Network (WLAN) has come into being. As the important component to lengthen the communication distance and enlarge the covering area of WLAN, the power amplifier (PA) and antenna functions with more and more significance.This article takes the application of PA and antenna in WLAN as the clue, and makes research and experiment implement of the non-linear distortion occurring in PA and networking antenna technique. The article firstly introduces the linearization techniques: predistortion technique and technique feedforward. It analyses the concept and causes of the nonlinear distortion, and consequently introduces the principle and implement of predistortion and feedforward, and puts forward the innovative project of self-adaptable predistortion and feedforward. Then it gives the circuit design of the PA’s application of in WLAN and pays more attention to the linearization. Finally it illustrates WLAN networking antenna technique, analyses the theory basis and WLAN application of it and introduces the present hot technique of smart antenna.On the aspect of PA linearization, a project combining predistortion with feedforward is presented in principle in this article. This project takes the advantage of two techniques and overcomes their defects, which takes effect on PA linearization. On the aspect of networking antenna, this article discusses the application of smart antenna used in WLAN, which makes it meet users’ need ingreat area.For the WLAN application more and more widely, people’s needs have risen quickly accordingly. The research results of this article has great significance on enlarging Covering Square in WLAN technology, settling with the problem existing in the process of signals transmit and receiving, improving the communication property of WLAN.更多还原