《物理-DDS信号源设计》-毕业论文（设计）.doc

目 录 摘 要………………………………………………………………………………………1 Abstract……………………………………………………………………………………1 1概述………………………………………………………………………………………1 1.1 DDS技术简介……………………………………………………………………1 1.2系统概述…………………………………………………………………………2 1.3主要技术及性能指标……………………………………………………………2 2总体设计…………………………………………………………………………………2 2.1系统框图…………………………………………………………………………2 2.2工作原理…………………………………………………………………………2 3系统方案论证……………………………………………………………………………3 4系统所用主要器件介绍…………………………………………………………………4 4.1 AD9850芯片介绍………………………………………………………………4 4.2 AT89C51芯片简介………………………………………………………………7 5硬件电路…………………………………………………………………………………9 5.1键盘扫描及显示电路模块………………………………………………………9 5.2 AD9850波形产生电路模块…………………………………………………10 6软件设计…………………………………………………………………………………12 6.1程序流程…………………………………………………………………………12 6.2键盘及显示部分程序……………………………………………………………12 6.3 AD9850波形产生程序…………………………………………………………14 7设计的制作与调试………………………………………………………………………14 7.1硬件调试…………………………………………………………………………14 7.2 软件调试……………………………………………………………………14 8结束语…………………………………………………………………………………15 参考文献…………………………………………………………………………………15 致谢………………………………………………………………………………………16 附录………………………………………………………………………………………17 PAGE DDS信号源设计 摘 要：直接数字合成（DDS）是一种重要的频率合成技术，具有分辨率高、频率变换快等优点，在雷达及通信等领域有着广泛的应用。本文介绍了一种直接利用DDS（直接数字频率合成器）芯片AD9850及单片机AT89C51组成的简单的DDS信号发生器的设计，讨论了频率和相位控制字的计算方法以及标准正弦信号、调频信号的产生方法，给出了相应的硬件电路和软件流程。 关键词：直接数字频率合成；AT89C51；AD9850；信号发生器 Design of the Signal Source Based on DDS Abstract: Direct digital synthesis is a kind of important technique on frequency synthesis. It has many advantages， such as higher frequency resolution， faster frequency transform， and so on. It is widely used in radar， communication and many other fields. This paper presents the design of a simple DDS signal generator which consists of AD9850 and AT89C51.discusses the method of controlling word with frequency and phase， as well as the way of generating standard sinusoidal signal and frequency modulated signal. Finally， it gives structure of the hardware circuit and software. Key words: Direct digital synthesis；AT89C51；AD9850；Signal generator 1概述 1.1 DDS技术简介 近年来，随着频率合成技