文档介绍：青岛理工大学
毕业设计(论文)
题目采用PLL技术的接收机
射频前端的设计
学生姓名: 吴迪
指导教师: 陈晓维
通信学院电子信息专业信息101 班
2014年6月14日
摘要

射频接收机前端电路是无线通信系统的一个不可缺少的重要组成部分,其性能的好坏直接影响着整机的性能。本文选取超外差式接收机作为研究对象。首先对射频接收机基本概念和发展历程进行了阐述,并围绕着射频前端的滤波器、低噪声放大器(LNA)、PLL技术的本地振荡电路、混频器来展开,进行了方案对比并选取最优方案,进而对系统进行理论基础上的优化。
本文通过对接收机的研究,分析了超外差式接收机的特点,对比分析了几种常见接收机的结构特点和工作原理,并给出了影响接收机性能的重要性能指标,提出了一种采用PLL技术的接收机射频前端的方案,并采用了二次混频技术兼顾了高低中频的利弊,同时滤除镜像干扰,最后对射频前端的关键技术性能指标进行了分析。该系统通过ADS2008软件的理想元器件对系统进行仿真,设计了一个频率段在88MHz-108MHz的频率接受机系统。
关键词: 射频接收机,低噪声放大器,PLL,二次混频
ABSTRACT
The RF receiver front-end circuit is an ponent of a munication stand or fall of its performance directly affects the performance of the article selects the superheterodyne receiver as the main of all, basic concept and development of rf receiver are expounded,And around the RFfilter low noise amplifier (LNA) local oscillation circuit of PLL technology and mixer,parison and selection of the optimal solution, and then on the basis of the theory of optimization of the system.
In this paper, based on the research of the receiver, analyzed the characteristics of superheterodyne receiver, comparison and analysis of mon receiver structure characteristics and working principle of importance and influence the performance of receiver is given performance index, this paper proposes a receiver rf front-end solutions using PLL technology, using the secondary mixing bine the advantages and disadvantages of high and low frequency, at the same time, filter out the mirror interference, finally, the key technology of rf front-end performance index are analyzed ,The system is simulating through ADS2008 software system ponents , and finally we have designed a receiver systemin the frequency of 88 MHz to 108 MHz.
KEY WORDS: Rf receiver,sow noise amplifier,PLL,secondary mixing

目录
第1章绪论 1
研究背景 1
无线通信系统简介 2
课题的主要研究内容 3
第2章接收机前端电路 4
接收机的基本结构 4
接收机类型 4
零频接收机 4
数字中频接收机 5
超外差式接收机 6
7
第3章超外差前端