【正文】 第 I 頁 基于 FPGA 的失真度測試儀 摘 要 在電子工程的設(shè)計和應(yīng)用中，信號無論在開路傳輸或閉路傳輸過程中都受到環(huán)境、傳輸網(wǎng)絡(luò)的工作狀態(tài)和應(yīng)用元器件參數(shù)變化的影響使其或多或少的改變了原有信號的性質(zhì)，這種變化就是所謂的信號畸變現(xiàn)象，通常叫做失真。信號的失真分為三種 :頻率失真，相位失真和波形失真。波形失真又稱非線性失真，它是由放大電路的非線性引起的，非線性失真又包括諧波失真和互調(diào)失真。 通過非線性失真測試可以考察傳輸網(wǎng)絡(luò)的失真性質(zhì)，有利于改進(jìn)傳輸網(wǎng)絡(luò)的性質(zhì)。因此在信息產(chǎn)生，傳遞，接受過程中，必須認(rèn)真分析處理 好失真問題。各種非線性失真測試儀在電力、電子、通信領(lǐng)域中得到廣泛應(yīng)用。常用的失真度檢測儀器按測量原理大致可分為二大類 :基波剔除法和頻譜分析法。一般模擬式的測量儀采用基波剔除法，其缺點是需要提供未失真的基波信號而且其低頻測量精度低。頻譜分析法是用頻率分析儀測量各次諧波的方法計算出波形失真度，但采用此種方法的儀器價格較昂貴。 隨著微型計算機(jī)、單片機(jī)尤其是數(shù)字處理芯片 DSP的發(fā)展與應(yīng)用，本文提出了一種基于 DSP芯片的采用快速傅立葉變換 (FFT)算法，計算出信號基波及各次諧波的電壓有效值，從而根據(jù)失真度計算公式計算 失真度的測量方法。論文首先介紹國內(nèi)外傳統(tǒng)失真度分析儀的測量方法及應(yīng)用前景，然后對幾種測量方案進(jìn)行比較并選擇較好方案，然后進(jìn)一步闡述并分析該方案的硬件實現(xiàn)和軟件實現(xiàn)及其 matlba 仿真結(jié)果，接著對該方案的軟硬件測量誤差進(jìn)行分析，最后是全文的總結(jié)。 關(guān)鍵詞 ： FFT； FPGA； 失真度 第 II 頁 Abstract In the design and application of electronic engineering， both in open circuit and in closed circuit， signal is certainly affected by environment， the status of the transport work and the change of parameters of the ponent applied. Then the characters of useful information will be changed more or less and the change is generally called as distortion， namely socalled signal distortion. Signal distortion includes three kinds of distortion: frequency， phase and waveform .The waveform distortion ic caused by the nonlinearity of the amplifier circuits it is often called as nonlinearity distortion. The nonlinearity distortion also include harmonic distortion and intermodulation distortion. We can test the charater of the transport newtok by detecting the nonlinear distortion and this is useufl to improve the character of the newtork. In the generation， transport and reception of singal， we must careuflly analyze and handle distortion. Kinds of nonlinear distortion meters have been widely used in many fields such as electronies， electricity and munication， and so distortion meters used in mon generally be divide in tow kinds as the method of theory of test. They are the method of suppressed first frequency and the method of frequeney table analysis. Most of analog distortion meters apply the method of suppressed fisrt frequency. But the disadvantages are need to suppply the first frequency and the lower test precision of the low method of analysis frequency table is using the meter of frequency table to test all kinds of frequency and then calculate the distortion of the wave. But the meter of analysis frequency tbale is more expensive. As the development of microputer and singlechip， especially the DSP chip ， The paper advance a method of measure the disotrtion of sine singal， which is using the DSP chip to carry out the FFT to get the magnitude of all kinds of frequency then using the formula calculate the distortion. The paper fisrt introduce the measure method of generally diostrtion meter of internal and overseas and the application of the meter and secondly pare several measure mehtods， then choose the best method and expound how to carry out this measure method in hardware and sotfware. Using matlab emulate the method and show the result. At the last give the erro analysis of hardware and software during the measurement and the summarize. Keywords: FFT ； FPGA； distortion. 第 III 頁 目 錄 摘 要 .................................................................................................................................I ABSTRACT............................................................................................................................... II 第 1 章 緒 論 ................................................................................................................. 1 本論文的背景和意義 ........................................................................................... 1 失真度測試儀介紹 ............................................................................................... 1 失真度測試儀的發(fā)展?fàn)顩r ................................................................................... 2 技術(shù)指標(biāo) ............................................................................................................... 3 第 2 章 軟件工具介紹 .............................................................................................. 4 FPGA基本知識 .................................................................................................. 4 FPGA 的基本結(jié)構(gòu)簡介 .......................................................................... 4 FPGA 的設(shè)計流程 .................................................................................... 4 QUARTUS II基本知識 ...................................................................................... 8 Quaturs II 的優(yōu)點功能簡介 ............................................................ 4 Quaturs II 設(shè)計流程 .......................................................................... 4 DSP技術(shù)簡介 .......................................................................................... 9 現(xiàn)代 DSP 實現(xiàn)方案及設(shè)計流程概述 ................................................. 4 基于 FPGA 的 DSP 設(shè)計 ......................................................................... 4 PROTEL DXP 簡介 .................................................................... 錯誤 !未定義書簽。 第 3 章 方案設(shè)計 .......................................................................................................... 4 提出方案 ........................................................................................................... 1 方案選擇 ........................................................................................................... 1 系統(tǒng)整體設(shè)計思路 ....................................................................................... 2 A/D轉(zhuǎn)換電路 ................................................................................................... 1 FPGA 的基本結(jié)構(gòu)簡介 ................................................................................. 4