基于單片機的函數(shù)信號發(fā)生器設(shè)計

測控論文編號:CK057   論文字數(shù):11150,頁數(shù):32

目 錄
摘要 ……………………………………………………………………………...……………. Ⅰ
1 前言 …………………………………………………………………………………………..1
2方案論證 …………………………………………………………………………………. . .3
2.1  波形生成方案 …………………………………………………………………….……3
2.2  波形生成原理  ……………………………………………………………………......4
2.3  頻率變化范圍及步進論證  ……………………………………………………...……5
2.4  輸出電壓幅度變化范圍及步進論證   ………………………………………………6
2.5  穩(wěn)幅論證 ………………………………………………………………………………7
2.6  波形存儲論證…………………………………………………………………………..7
2.7  波形顯示………………………………………………………………………………..7
2.8  頻譜分析論證 ………………………………………………………………………….8
2.9  失真度分析論證 .………………………………………………………………………9
2.10 掃描輸出….………………………….…………………………………………………10
3  系統(tǒng)設(shè)計………………….………….…………………………………………………...11
 3.1  總體設(shè)計……………………………………………………………………………….11
  3.1.1  系統(tǒng)框圖………………….…………………………………………………….11
  3.1.2  各模塊說明…………………….……………………………………………….11
 3.2  各模塊設(shè)計及參數(shù)計算……………….………………………………………………12
        3.2.1  頻率參數(shù)計算、EPLD設(shè)計……………………………………………………12
        3.2.2  幅度控制、雙D/A設(shè)計………….……………………………………………13
        3.2.3  濾波、緩沖輸出電路設(shè)計…………..…………………………………………13
        3.2.4  液晶顯示、鍵盤輸入…………………..………………………………………14
        3.2.5  單片機最小系統(tǒng)……………………..…………………………………………14
        3.2.6  任意波形輸入………………………..…………………………………………14
        3.2.7  掉電存儲……………………………..…………………………………………15
        3.2.8  對A/D信號采樣進行頻譜分析……..…………………………………………15
 3.3  軟件系統(tǒng)………………………….……………………………………………………15
  3.3.1  軟件系統(tǒng)流程框圖……………………………………………………………..16
  3.3.2  波形發(fā)生程序和波形回放程序………………………………………………17
  3.3.3  A/D采樣輸入與存儲程序、觸摸屏輸入與存儲程序………………………17
        3.3.4  系統(tǒng)設(shè)計圖……………………………………………………………………19
        3.3.5  印制PCB圖……………………………………………………………………20
4  調(diào)試……………………….……………………………………………………………..21
 4.1  硬件調(diào)試…………………………………………………………………………...…21
  4.1.1  EPLD控制電路的調(diào)試………………………………………………..……...21
  4.1.2  高頻電路抗干擾設(shè)計…………………………………………………...…….21
        4.1.3  運算放大器的選擇………………………………………………….………..21
 4.2  軟件調(diào)試....................………………………………………..…………21
 4.3  軟硬件聯(lián)調(diào) ……………………………………………………….……..………….22
5  指標測試………………..………………………………………………………….. .…23
 5.1  測試儀器………………………………………………………………….…………23
 5.2  指標測試………………………………………………………………….…………23
 5.2.1  輸出波開頻率范圍測試……………………………………………………..23
 5.2.2  輸出波形幅度范圍測試…………………………………….……………….24
6  結(jié)論………………………………………………………………………….……………...25
 
致謝………………………………………...26

摘  要
 信號發(fā)生器又稱信號源或振蕩器，在生產(chǎn)實踐和科技領(lǐng)域中有著廣泛的應(yīng)用。各種波形曲線均可以用三角函數(shù)方程式來表示。能夠產(chǎn)生多種波形，如三角波、鋸齒波、矩形波（含方波）、正弦波的電路被稱為函數(shù)信號發(fā)生器。函數(shù)信號發(fā)生器在電路實驗和設(shè)備檢測中具有十分廣泛的用途。例如在通信、廣播、電視系統(tǒng)中，都需要射頻（高頻）發(fā)射，這里的射頻波就是載波，把音頻（低頻）、視頻信號或脈沖信號運載出去，就需要能夠產(chǎn)生高頻的振蕩器。函數(shù)信號發(fā)生器的實現(xiàn)方法有多種，利用專用直接數(shù)字合成ＤＤＳ芯片的函數(shù)發(fā)生器：能產(chǎn)生任意波形并達到很高的頻率，但其成本較高。
關(guān)鍵詞：信號發(fā)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