简易频谱分析仪的设计本科毕设论文.doc

沈阳工程学院毕业设计（论文）简易频谱分析仪的设计PAGE\*MERGEFORMAT-46-PAGEIII摘要频谱分析仪的基本功能是测量信号的幅度/频率响应，可以完成诸如频谱成分分析、失真测量、调制信号谱分析、信号衰减测量、电子组件增益测量等。其基本工作原理是，扫频本振的频率随锯齿波发生器的输出在一定范围内扫描，使不同频率的输入信号与本振混频后，依次落入分辨率带宽滤波器通带内，进一步放大、检波后加到Y放大器，亮点在屏幕上的垂直偏移正比于该频率分量的幅值。由于扫描电压在调制振荡器的同时，又驱动X放大器，从而可以在屏幕上显示出被子测信号的频谱。本系统是根据外差原理设计并实现的频谱分析仪。利用DDS芯片生成10KHZ步进的本机振荡器，AD835做混频器实现频率的合成，通过滤波器取出各个频点（相隔10KHZ）的值，再配合放大，检波电路收集采样值，经单片机SPCE061A处理，最后送给示波器显示频谱。测量频率范围覆盖1—30MHZ，该系统也可以根据用户的需要设定显示频谱的中心频率和带宽，还可以识别调幅，调频和等幅波信号。关键词频谱分析，混频，滤波，外差原理AbstractSpectrumanalyzertomeasurethesignalisthebasicfunctionoftheamplitude/frequencyresponsecanbefinishedsuchasspectrumcompositionanalysis,distortionmeasuring,modulationsignalspectrumanalysis,signalattenuationmeasure,electroniccomponentgainmeasurements.Basicworkingprincipleis,sweepfrequencythisthevibrationofthefrequencywiththeoutputofsawtoothwavegeneratorinacertainrangeofdifferentfrequencyscanning,maketheinputsignalandtheresonancefrequencymixing,ordinalfallwithinbandpassfilterbandwidthresolution,furtheramplification,afterdetectionofamplifier,highlightsaddedtoYinscreenisproportionaltotheverticalmigrationoftheamplitudefrequencycomponents.Duetoscanvoltageinmodulationoscillator,andmeanwhile,thuscandriveXamplifierisshownonthescreeninthespectrumofthemeasuredsignalquilt.Thispaperadoptsheterodyneprincipledesignandrealizethespectrumanalyzer.Use10KHZDDSchipgenerationstepofthismachineoscillators,AD835domixers,throughthefilterremoveeachfrequency(10KHZ)valueapart,coupledwithamplifier,detectioncircuittocollectsamplesvaluesofsunplusSPCE061AprocessingbyMCU,finallysendoscilloscopedisplayspectrum.Measurefrequencyrangecovers1-30MHZaccordingtouserneedtosetthedisplayspectrumofcenterfrequencyandbandwidth,stillcanidentifyam,FMandamplitudewavesignal.KEYWORDSSpectralanalysis,mixing,smoothing,heterodyneprinciple目录TOC\o"1-4"\h\uHYPERLINK\l"_Toc390185069"摘要PAGEREF_Toc390185069\hIHYPERLINK\l"_Toc390185070"AbstractPAGEREF_Toc390185070\hIIHYPERLINK\l"_Toc390185071"1绪论PAGEREF_Toc390185071\h-1-HYPERLIN