实验 8 设计切比雪夫 II 型无限冲击响应带通滤波器实验内容：用 fdatool 工具设计一个切比雪夫 II 型无限冲击响应带通滤波器。滤波器指标：归一化通带 边界频0.4、0.5,归一化阻带边界频率0.1、0.8,通带波纹ldB,最小阻带衰减100dB、lOOdB, 滤波器选用最低阶形式。注：在以下每个部分的测试中，都展示了两幅图，第一幅是option=stopband，第二幅是 option=passband.创建过程：首先在命令行中输入open fdatool,就会打开fdatool.m文件，之后运行fdatool.m文件，就可 以打开fdatool GUI界面，然后按照要求输入数值：Response type=bandpass;Design method=IIR, Chebyshev type 2;Filter order=minimum order;Option: match exactly=stopband/passband;Frequency specifications:Unit=Normalized;Wstop1=0.1; wpass1=0.4; wpass2=0.5; wstop2=0.8;Magnitude specifications:Unit=dB; Astop1=100; Apass=1; Astop2=100;这样，由于fdatool GUI功能的强大，切比雪夫2型滤波器就设计完成了。一开始我认为衰 减的dB值应该为负，所以在Astop1=-100, Astop2=-100;但是这时点击design filter会提示 让输入正值。我查看了滤波器的一下几个特性：Part 1 振幅谱nSiflrrSt Anelyi Tool - fuiiETlIedlfdc用Q Q XKJ刃ELI田出T j-Eral1 ho O S File Edit An al/sis Targets vie/i window Helpi Mgnffijdo 尺 0和2日 i；dB；iiCurrent Fiter htarmalioriaruciure: Irect-FormI.Second-Order SectfcnOrder10Secflons 5St*巾：Ve&Saurce:DesignedFit&-谄g凶.LoApasVH眇网55VBandpassBandstopDirrerencistcr-_ Desicr Melhod_RFIRChebyaher Type IEquriaphLoading filter. doneSpecify bderMrinium orderOpllCTlSMatcti eiadl?st邮阳胡-OcsiflfrSt Anelysis Tool - Imutiedlfda urts：rjcrniaized (Otoi)wpEEa2:wdop2wsiopl:Wp&S1：LUils： dBAstapl: ICCApa&s:1凸岀叩21C0二口:更.二也岂.二H刃EZ1田汕T j-Eral1 ho O S File Edit An al/sis： Targets viei window llmlpl MagriHude ResMnse fdBiiCurrent Fiter htarmslioriaruclure: Direct-Form I,SccDrd-OrderOrder10Eecflons: s显辭鼎：YesEaurce:Dc$igned二二二二二甄注餌二二二二二 JFitrfr- r/lEriager Response TypeLowpassHiipassBandpassBandstopDirrerenc later-_ Desicr Melhod.IR Chebysher Type N冋尺 Equripple&0.1止3 Q.4&.S&.6 &J HE 0.&Ncrmslizsd Frsqu-ency |戈忑 red. BaMplBFiler OrderSpecify orderMrinium orderOpllCTlSMatcti eiadly卩卿s&arici钙Frequency SpecmcsIiDns.M3： NoEim壮ud (Otoi)F& 43Siop1： 0-1wp&sl: 0 iWpEES2：vsiop2_ ME-irlude Specircstio仃窑.Ltiils: dBAstnpl: 1-i凸戶理 1Aiiop2 1200.5a.aLoading filter. done可以看到如果选择的是passband exactly match,那么通带相对上一个而言变窄。Part 2相位谱用E Q XKJ 0S誥咅匝1厂鸥1 ho O S File Edit An al/sis Targets vie/i window 旦 mlpl Phase ResponseiCurrent Fiter htarmaliori3ruclure: Direct-Form I.Second-Order SectfcnOrder10Secflons 5St*巾：Ye&St 丁匕 FHerFit&-曰LowpasiVV Response Type.EandpassBandstopDirrerencHcr-_ Desicr Melhod.Chebyshev Type IIFIREquiripplebiter Order迦坯辿巴妲JMrimum orderOpllCTlSMatcti eiadly st-ibsnd -l Frequency speDmcsIiDns.ftaTnaizcd (0to1)Fswsiopl:Wp&S1：WPEE32：wdop2,_Magnnud$ specirctio 仃窑,LUils： dBAstapl: 100Apa&s:IA1op2 1CGSaurce:Designed二 ULd”.二吐 UDesigning Filter. Doneiher Design Bt Aridlysis TooT - luntilledUd *rnnrjrFile Edit An al/sis; Targets vis/i window 旦 mlp / 口昌a E Q龙X e 題区I ELI田汕7門厂 Current Fiter htai-msliDriHruclure: Direct-Form I,Second-Order SuciknuorderlaEecflons: ststle:YesEaurce:DeignedStrre FUerFits- rEtiagei .-5&0.1 G2 止3 0.&.S &币 0.70.-B0.9NcrmslizEd FrsqL-encv rGd.E-ampiB Response Type.Fiter Orderra+l- EOLowpassSpecify orderFrequency Specificslions.M3： fJcrmaized (0 to 1J_ Magnilude Epecifcatio仃窑.Ltiils: dBzn岂Hi才1曲55EsndDaasBandstopDirrerenctetcr-_ Desicr Melhod.Mrinvum orderOpllCTlSMatcti eiadly MAstnpl:IZCtoFl尺Chebyshev Type IIEquirijaplewpEEs2:wsiopZwdopl：Wp&S1：Aiiop21ZCDesiffi Fill口Computing Response. donePassband在通带的相位变化更明显一些。Part 3群延迟i 弘 Analysis TmI - Fill云EFTc 十用E Q X刃EZ1田出T j-E3Era!1 ho O S File Edit An al/sis Targets viei window llRp!Group DelayiCurrent Fiter htarmaliori3ruclure: Direct-Form I.Second-Order SectfcnOrder10Secflons 5St*巾：Ye&Saurce:DesignedStere FUer .Filar f准r诣g凶.關IzqIBralICTrffiLwpmvHiipassV.BandD338Bandstop-DHTerenlatffV Response Type._ Desicr MelhodR Chebyher Type H v 冃尺 EquriapleComputing Response. done& Analysis Tool - IimtilledBfdd V韜IzqIBfa轉诩创biter OrderSpecify cr is;；Miiniuni orderOpllCTlSMatcti eiadly st-bsnd -l Frequency speDmcsIiDnsLrts： rtarnaised (0 tg 1)Fe：- 7 ：ii1i |(i111111111I11J 1