单位代码01学号__分类号_TN713+.4__密级______毕业设计说明书低通滤波器电路设计与实现院（系）名称专业名称学生姓名指导教师2012年5月10日低通滤波器电路设计与实现摘要滤波器是一种二端口网络。它具有选择频率的特性，即可以让某些频率顺利通过，而对其它频率则加以阻拦。目前由于在雷达、微波、通讯等部门，多频率工作越来越普遍，对分隔频率的要求也相应提高，所以需用大量的滤波器。再则，微波固体器件的应用对滤波器的发展也有推动作用，像参数放大器、微波固体倍频器、微波固体混频器等一类器件都是多频率工作的，都需用相应的滤波器。低通滤波器是一个通过低频信号而衰减或抑制高频信号的部件。理想滤波器电路的频响在通带内应具有一定幅值和线性相移，而在阻带内其幅值应为零。有源滤波器是指由放大电路及RC网络构成的滤波器电路，它实际上是一种具有特定频率响应的放大器。滤波器的阶数越高，幅频特性衰减的速率越快，但RC网络节数越多，元件参数计算越繁琐，电路的调试越困难。根据指标，本次设计选用有源二阶巴特沃斯低通滤波器可达到本次设计要求的指标，可调增益部分通过电压跟随器和反相放大器来实现可调增益。关键词：低通滤波器，巴特沃斯滤波器，频率响应Low-passfiltercircuitdesignandAchieveAuthor:ShangShiweiTutor:SongJiayouAbstractFilterisakindoftwo-portnetwork.Ithasthecharacteristicsoffrequencychoice,thatcanmakesomefrequencypass,buttootherfrequencyistostop,becausenowinradar,microwave,communication,andotherdepartments,moreworkfrequencyisbecomingmoreandmorecommon,therequirementsofthefrequencyofspacealsoincrease;Soneedalotoffilter.Moreover,theapplicationofmicrowavesoliddeviceforthedevelopmentofthefiltercanboost,asparametersamplifiers,microwavesolidtimesfrequencydevice,microwavesolidmixers,kindofdeviceisworkingfrequency,needcorrespondingfilter.Lowpassfilterisathroughthelowfrequencysignalandattenuationorinhibitthehighfrequencysignalcomponents.Idealfiltercircuitfrequencyresponseinbandpassshouldhavecertainamplitudeandlinearphaseshift,andinwhichtheamplitudewithinnerresistanceshouldbezero.ActivefilteristopointtobyamplifyingcircuitandnetworkstructureofRCfiltercircuit,itisactuallyaparticularfrequencyresponseoftheamplifier.Theordernumberoffilter,thehigheramplitudefrequencycharacteristicsoftheattenuationratefaster,butRCnetwork'sday,morecomponentparametersarecalculatedthemoredetailed,themoredifficultthecommissioningofthecircuit.Accordingtotheindex,thedesignchooseactivesecondorderbartwolow-passfiltercanachievethedesignrequirementsoftheindex,adjustablegainthroughthevoltageoffollowandreversed-phaseamplifiertoachieveadjustablegain.Keywords:Low-passfilter,Butterworthfilter,Frequencyresponse目录1引言.........................................................................................................................................11.1本课题的研究背景、发展及意义................................................................................21.2本次设计的基本内容....................................................................................................32基本理论介绍.........................................................................................................................42.1滤波器分类及特性........................................................................................................42.2低通滤波器的作用和结构............................................................................................62.2.1低通滤波器的主要技术指标.............................................................................62.2.2简单一阶低通有...
