毕业设计论文-基于DDS9850的正弦波信号发生器的设计.docVIP

基于DDS9850的正弦波信号发生器的设计 摘 要 传统的正弦波信号发生器大多是基于模拟电子技术设计制作的，这种信号源制作简单，成本低廉，但是它的缺点也很多，比如不便于存储，频率稳定度差，失真度高等。DDS是以全数字技术，从相位概念出发直接合成所需波形的一种新的合成原理。本设计采用DDS和单片机技术相结合，以DDS芯片AD9850为核心设计了一种幅度、相位、频率都可调节的正弦波信号发生器，它不仅能克服传统的正弦波信号发生器的缺点，而且由模拟乘法器产生调幅电路、采用数字键控的方法实现二进制PSK、ASKDDS AD9850 单片机 The design of sine wave signal generator based on DDS9850 ABSTRACT Most of the traditional sine wave signal generator is designed based on analog electronic technology, this is simple and low cost production source, but it has many shortcomings, such as it is not easy to store,its frequency stability is poor, high distortion and so on. DDS is a new synthetic principle which based on the all-digital technology, starting from the concept of phase direct synthesis of waveforms required.This design uses DDS and microcontroller technology, the AD9850 DDS chip to the core ，design a sine wave signal generator，whose magnitude, phase, frequency can be regulated.It’s not only can overcome the traditional shortcomings of the sine wave signal generator, and the amplitude circuit is produced by the analog multiplier , the digital keying is used to achieve binary PSK, ASK signal, and it has wide band, high frequency stability, wave good. The signal generator has a stronger market competitiveness, in the frequency hopping, radio communication technology has relatively broad prospects for development. KEY WORDS Signal Generator DDS AD9850 MCU 目 录 中文摘要 I 英文摘要 II 1 概 述 1 2 方案论证 2 2.1 主控制器 3 2.2 正弦信号产生 3 2.3输出电压放大 4 2.4 FM调频电路 4 2.5 AM调幅电路 5 2.6 产生二进制PSK、ASK 5 3 详细软硬件设计 7 4 硬件模块设计 8 4.1 SPCE061A简介 8 4.1.1 综述 8 4.1.2 性能 8 4.1.3 结构概览 9 4.1.4 芯片的引脚排列和说明 10 4.2 正弦信号产生模块 14 4.2.1 AD9850芯片简介 14 4.2.2 AD9850工作方式介绍 15 4.2.3相位控制字的计算 16 4.3 带负载输出 18 4.3.1推挽放大器 19 4.4正弦调制信号的产生 20 4.5 AM调幅信号的产生 21 4.6 ASK、PSK的产生 22 4.6.1 ASK: 幅移键控ASK (Amplitude Shift Keying) 22 4.6.2 PSK：数字相位调制（phase shift keying） 23 4.6 LCD 26 4.6.1 概述 27 4.6.2 基本特性 27 4.6.3 模块接口说明 28 4.6.4 控制器接口信号说明 29 5 软件设计 31 6 测试说明 32 致 谢 33 参考文献 34 附 录 35 1