论文编号:CK057论文字数:11150,页数:32
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中有着广泛的应用。各种波形曲线均可以用三角函数方程式来表示。能够产生多种波形，如三角波、锯齿波、矩形波（含方波）、正弦波的电路被称为函数信号发生器。函数信号发生器在电路实验和设备检测中具有十分广泛的用途。例如在通信、广播、电视系统中，都需要射频（高频）发射，这里的射频波就是载波，把音频（低频）、视频信号或脉冲信号运载出去，就需要能够产生高频的振荡器。函数信号发生器的实现方法有多种，利用专用直接数字合成ＤＤＳ芯片的函数发生器：能产生任意波形并达到很高的频率，但其成本较高。
关键词：信号发生器、波形、芯片
Abstract
Signal generator, also known as source or oscillator, in the areas of production practices and technology has a wide range of applications. Curves of various wave equation can be expressed by trigonometric function. Can produce a variety of waveforms, such as the triangle wave, sawtooth, square wave (with square wave), sine wave signal generator circuit is called the function. Function Generator experiments and equipment testing at the circuit has a very wide range of uses. For example, in telecommunications, broadcasting, television systems, require radio frequency (RF) transmitter, where the RF wave is the carrier, the audio (low frequency), the video signal or pulse signal carried out, we need to generate high-frequency oscillator. Function signal generator of means, using dedicated chips DDS direct digital synthesis function generator: to generate arbitrary waveforms and achieve very high frequency, but its high cost.
Keywords：signal generator、waveform、chip
目 录
摘要 ……………………………………………………………………………...……………. Ⅰ
1 前言 …………………………………………………………………………………………..1
2方案论证 …………………………………………………………………………………. . .3
2.1 波形生成方案 …………………………………………………………………….……3
2.2 波形生成原理 ……………………………………………………………………......4
2.3 频率变化范围及步进论证 ……………………………………………………...……5
2.4 输出电压幅度变化范围及步进论证 ………………………………………………6
2.5 稳幅论证 ………………………………………………………………………………7
2.6 波形存储论证…………………………………………………………………………..7
2.7 波形显示………………………………………………………………………………..7
2.8 频谱分析论证 ………………………………………………………………………….8
2.9 失真度分析论证 .………………………………………………………………………9
2.10 扫描输出….………………………….…………………………………………………10
3 系统设计………………….………….…………………………………………………...11
3.1 总体设计……………………………………………………………………………….11
3.1.1 系统框图………………….…………………………………………………….11
3.1.2 各模块说明…………………….……………………………………………….11
3.2 各模块设计及参数计算……………….………………………………………………12
3.2.1 频率参数计算、EPLD设计……………………………………………………12
3.2.2 幅度控制、双D/A设计………….……………………………………………13
3.2.3 滤波、缓冲输出电路设计…………..…………………………………………13
3.2.4 液晶显示、键盘输入…………………..………………………………………14
3.2.5 单片机小系统……………………..…………………………………………14
3.2.6 任意波形输入………………………..…………………………………………14
3.2.7 掉电存储……………………………..…………………………………………15
3.2.8 对A/D信号采样进行频谱分析……..…………………………………………15
3.3 软件系统………………………….……………………………………………………15
3.3.1 软件系统流程框图……………………………………………………………..16
3.3.2 波形发生程序和波形回放程序………………………………………………17
3.3.3 A/D采样输入与存储程序、触摸屏输入与存储程序………………………17
3.3.4 系统设计图……………………………………………………………………19
3.3.5 印制PCB图……………………………………………………………………20
4 调试……………………….……………………………………………………………..21
4.1 硬件调试…………………………………………………………………………...…21
4.1.1 EPLD控制电路的调试………………………………………………..……...21
4.1.2 高频电路抗干扰设计…………………………………………………...…….21
4.1.3 运算放大器的选择………………………………………………….………..21
4.2 软件调试....................……………………………………………………..…………21
4.3 软硬件联调 ……………………………………………………….……..………….22
5 指标测试………………..………………………………………………………….. .…23
5.1 测试仪器………………………………………………………………….…………23
5.2 指标测试………………………………………………………………….…………23
5.2.1 输出波开频率范围测试……………………………………………………..23
5.2.2 输出波形幅度范围测试…………………………………….……………….24
6 结论………………………………………………………………………….……………...25
致谢……………………………………………………………………………………………...26
基于单片机的函数信号发生器设计......