中波广播电台信号控制检测系统研究本文主要是基于单片机设计了一个频率特性测试仪，从而完成对中波信号的幅度频率等方面的采集和研究。本论文中设计的频率特性测试仪中DDS频率合成器使用了AD9854芯片，控制器使用Msp430芯片。利用零中频正交解调原理对待测网络针进行频率特性的测量，输入网络的信号源由DDS频率合成器提供，之后用DDS输出的两路正交信号和待测网络的输出信号通过模拟乘法器进行混频，并且将混频的结果通过低通滤波器获得对应幅频特性与相频特性的直流分量，输出经过A/D转换之后传递给主控器Msp430，同时MSP430会分析处理所测数据，从而测得待测网络的频率特性，在数据处理之后还会传递至LCD模块绘出相应的频率曲线图，至此完成对待测网络频率特性的测试。同时DDS的输出信号可以直接传递给Msp430，之后经过处理后的信号送入LCD模块，从而直接绘制出中波信号的波形，从而能够很好的对中波信号实施检测，并获得较为精确的频率与幅度等数据信息。33970
毕业论文关键词 单片机 中波信号 D/A转换 波形显示 频率特性
毕业设计说明书外文摘要
Title The research of test system of radio wave signal control
Abstract
This paper is designed a frequency characteristic testing instrument based on SCM,thus completing the collection and study of wave signal amplitude frequency. The frequency characteristic test instrument by AD9854 DDS frequency synthesizer, MSP430 controller, according to zero if quadrature demodulation principle of scanning frequency characteristics of the network will be measured, sine signal input DDS output measured network, two orthogonal signals respectively and the output of DDS export signal will be measured by multiplication by simulating mixing network multiplier, DC component made with amplitude frequency characteristic and phase frequency characteristic of the low pass filter, transmitted by high precision A/D converter to the MSP430 controller, and the test data were analyzed and processed by MSP430, the final measured amplitude frequency characteristic and phase frequency characteristic of the target network, and the corresponding characteristic curve is drawn by LCD. In order to complete the performance test to the target network. The system has low power consumption, low cost, convenient control, man-machine interface is friendly, stable performance characteristics to well on medium wave signal detection and get more accurate data.
Keywords SCM single wave signal D/A conversion
waveform display Frequency characteristic
目 次
1 引言 1
1.1 中波广播信号的定义 1
1.2 国内外基于单片机系统开发的现状 1
1.3 研究该课题的目的和意义 2
2 系统设计 3
2.1 系统方案的选择 3
2.2 芯片的选择 4
2.3 管脚说明 4
3 系统硬件设计 7
3.1 基本原理（总体框图） 7
3.2 各部分电路 7
3.2.1 DDS模块设计 7
3.2.2 DDS输出放大电路 8
3.2.3 乘法器电路 9
3.2.4 AD模数转换 9
3.2.5 键盘电路原理 10
3.2.6 LCD显示电路原理 12
4 系统软件设计 15
4.1 主程序设计 15 MSP单片机中波广播电台信号控制检测控制系统设计+电路图+程序:http://www.751com.cn/tongxin/lunwen_31308.html