摘要:信号发生器又称信号源或振荡器,在生产实践和科技领域有着广泛的应用。信号发生器是一种在科研和生产中经常用到的基本波形产生器,用来产生正弦波、方波、三角波、锯波等信号。
随着数字集成电路、微电子技术和EDA技术的深入研究,DDS技术以其有别于其他频率合成技术的优越性能和特点,成为现代频率合成技术中的佼佼者。
本课题是基于直接数字频率合成(DDS)原理,利用AT89C52单片机作为控制器件,采用AD9850型DDS器件设计一个信号发生器。该系统主要由控制模块、信号模块、显示模块、键盘输入模块构成。由信号发生器的硬件设计和软件设计参数,该系统可输出正弦波、方波,且频带较宽、频率稳定度高,波形良好。整个系统结构紧凑,电路简单,功能强大,可扩展性强。且该信号发生器具有强大的市场竞争力,在跳频技术、无线电通信技术方面具有比较广阔的发展前景。
关键词: 信号发生器;直接数字频率合成;AD9850芯片;AT89C52单片机
Abstract:Signal generator, also known as source or oscillator, in the areas of production practices and technology has a wide range of signal generator, also known as source or oscillator. Signal generator is a kind often used in scientific research and production of the basic waveform generator, used to generate sine, square, triangle wave, sawtooth and other signals.
As digital integrated circuits, microelectronic technology and in-depth study of EDA technology, its technology is different from other DDS frequency synthesizer technology and the superior performance characteristics of a modern frequency synthesis technology leader.
On the basis of direct digital synthesis(DDS) principle, a signal generator was designed, using AT89C52 single chip machine as the control device and adopting AD9850 type DDS device. The system mainly by the control module, signal modules, modules, a keyboard input module. Hardware and software design parameters were given. The system can output sine ware, square ware with wide frequency band, high frequency stability and good waveform. The whole system compact, simple circuit, powerful, scalable and strong. The signal generator has stronger marker competitiveness, with wider development prospect in frequency modulation technology and radio communication technology fields.
Key words: signal generator; direct digital synthesis; AD9850; AT89C52
信号波形发生器是一种常用的信号源,广泛应用与电子测量、自动控制和工程设计等领域。随着电子技术的发展,对信号源频率的稳定度、准确度以及频谱纯度的要求越来越高。DDS(直接数字合成)技术是从相位概念出发直接合成所需要波形的一种新的频率合成技术,与传统的模拟波形产生法相比,它具有相位变换连续、频率转换速度快、分辨率高、稳定度好、相位噪声小、便于集成、易于调整及控制灵活等多种优点。基于DDS技术的信号发生器是一种新型信号源,它已成为众多电子系统中不可缺少的组成部分。
本文主要介绍基于DDS的正弦波信号器的设计。该系统以AT89C52单片机作为控制器件,采用AD9850模块作为信号发生器,通过键盘矩阵调节频率的大小,液晶显示器中显示当前频率的数据,从而通过连接示波器,在示波器上显示波形的大小。该系统结构简单,抗干扰能力强,输出的波形稳定度高、波形良好。在通讯、导航、雷达、遥控遥测、电子对抗以及现代化的仪器仪表工业等领域广泛使用。