2007年全国大学生电子设计竞赛【本科组】音频信号分析仪（A题）摘要：本音频信号分析仪由8位MCU为主控制器，通过AD转换，对音频信号进行采样，把连续信号离散化，然后通过FFT快速傅氏变换运算，在时域和频域对音频信号各个频率分量以及功率等指标进行分析和处理，然后通过LCD对信号的频谱进行显示。该系统能够精确测量的音频信号频率范围为100Hz-10KHz，其幅度范围为100mVpp-5Vpp。关键词：快速傅里叶变换功率谱频谱Abstract:Theaudiosignalanalyzerisbasedona8-bitMCUcontroller,throughtheADconverterforaudiosignalsampling,thecontinuoussignaldiscrete,andthenthroughtheFFTfastFouriertransformcomputing,inthetimedomainandfrequencydomainofthevariousaudiofrequencysignalweightandpower,andotherindicatorsforanalysisandprocessing,andthenthroughtheLCDdisplaysignalsinthespectrum.Thesystemcanaccuratelymeasuretheaudiosignalfrequencyrangeof100Hz-10KHz,therangeof100mVpp-5Vpp.KeyWord：FFTPowerSpectrumFrequencySpectrum目录摘要：............................................................................................................................................11.系统设计....................................................................................................................................11.1设计要求............................................................................................................................11.1.1设计任务................................................................................................................11.1.2技术指标................................................................................................................11.2方案比较与选择................................................................................................................21.2.1采样方法比较与选择............................................................................................21.2.3信号功率计算方案比较........................................................................................31.3方案论证............................................................................................................................32.单元电路设计及参数计算...........................................................................................................32.1前级阻抗匹配和放大电路设计........................................................................................32.2抗混叠低通滤波器设计....................................................................................................53.软件设计....................................................................................................................................63.1程序总体流程图................................................................................................................63.2程序清单（见附录2）.....................................................................................................64.系统测试......................................................................................................................................64.1测试仪器............................................................................................................................64.2测试结果............................................................................................................................75.结束语....................................................................................
