CH3 无源器件的设计仿真与优化

电磁工程设计与仿真第三章微波无源器件

设计、仿真与优化主要内容3.2波导T接头的仿真3.1波导T接头的原理3.3波导T接头的优化3.4波导魔T的仿真3.1波导T接头的原理一、功分器的基本特性功率分配器（功分器）是无源三端口器件.特性：所有端口都匹配的三端口无耗互易网络是不可能的。三个条件任意一个条件放宽，则可以实现:若三端口网络非互易，则所有端口可匹配，并无耗。若无耗互易的三端口网络只有两个端口匹配，可实现。若三端口网络有耗，则该网络互易，全部端口可匹配。二、波导H-T，E-T3臂：H壁1,2臂:平分臂分支在主波导TE10磁场(H)平面内，因此称H-T1.波导H-T功率分配功能：1233臂自身有反射，若在该分支波导加入匹配装置，可使3臂匹配，入射功率全部从1、2臂平分输出。3臂输入时，从1/2臂等幅、同相输出；1.波导H-T应用：波导功率分配网络1臂输入时，2、3臂输出；1、2臂不隔离。2臂输入时，1、3臂输出；1、2臂不隔离。1231231.波导H-T问题：1,2不隔离有何影响？求和功能：123信号1信号2信号1＋信号2两信号分别从1、2臂输入，且到达分支波导中轴T面时相位相同，则3臂输出两信号之和，称为和信号。T1.波导H-T求差功能：123信号1信号2信号1－信号2两信号分别从1、2臂输入，且到达分支波导中轴T面时相位相反，则3臂输出两信号之差，称为差信号。

若此时两信号等幅，则3臂无输出；T1.波导H-T2.波导E-T21,2：平分臂3：E臂分支在主波导TE10电场(E)平面内，因此称E-T功率分配功能：2133臂自身有反射，但若在该臂加入匹配装置，可使3臂匹配，入射能量全部从1、2臂平分输出。3臂输入时，从1、2臂等幅、反相输出；2.波导E-T1臂输入时，2、3臂输出；1、2臂不隔离。1231232臂输入时，1、3臂输出；1、2臂不隔离。2.波导E-T求差功能：123两信号分别从1、2臂输入，且到达分支波导中轴T面时相位相同，则3臂输出两信号之差，称为差信号。信号1－信号2信号1信号2

若两输入信号等幅，则3臂无输出。T2.波导E-T求和功能：两信号分别从1、2臂输入，且到达分支波导中轴T面时相位相反，则3臂输出两信号之和，称为和信号。123信号1＋信号2信号1信号2T2.波导E-T3.T接头匹配波导T等效模型：T形结并联导纳：忽略B=0，且Z1=Z2=Z0,输入不匹配。3.波导H-T匹配3臂匹配方法：隔片匹配切角匹配销钉匹配根据三端口特性：由于H-T互易无耗，当3臂匹配时，1,2臂肯定不匹配。三.双T和魔T(1)双T根据E-T，H-T特性，双T特性：①输入：②③等幅同相输出，

④隔离；④输入：②③等幅反相输出，

①隔离；②③输入：①输出和信号，

④输出差信号；“①④臂隔离”原因：243T4臂输入的TE10模式关于中轴面T反对称，而1臂中TE10模式关于中轴面T对称，故相互不能激励。1臂（4臂）输入的TE10模可以在4臂（1臂）中激励起高次模，但高次模式不能传输，不能输出。4输入，1隔离243T1输入，4隔离(1)双T(2)魔T234（E）1（H）调配装置魔T=匹配双T(3)隔离性：①④隔离；②③隔离；

主要特性：匹配性：每个端口匹配；①④匹配，②③自动匹配；(2)平分性：

①输入：②③等幅同相输出;

④输入：②③等幅反相输出;②③输入：④=差，①=和;单脉冲雷达和差网络：ΣΔΣΔΣΣΔ(3)魔T的应用和波束差波束俯仰差和激励方位差测角功能(3)魔T的应用ΣΔΣΔ3.2波导T接头的仿真1.T接头仿真要求：波导尺寸：a=0.90in,b=0.4in隔片尺寸：W=0.45in,t=0.1in,offset=0or0.2in频率范围:8-10GHz分析端口反射和功率分配情况，为优化提供支持2.SetuptheDesignOpenHFSSandSaveaNewProject:Tee.hfssInsertandrenametheDesign:TeeModelSelectaSolutionType:DrivenModalSettheDrawingUnits:in3.CreatetheModelCreatetheT-Junction:DrawaBox(Tee

):basecorner(0,-0.45in,0)Dx=2in,Dy=0.9in,Dz=0.4inDuplicatetheBox:Edit>Duplicate>AroundAxis(z),90°DuplicatetheBoxtoCreatetheThirdSection:-90°3.CreatetheModelCreatetheT-Junction:UnitetheBoxes:Modeler->Boolean->Unite将T接头Copy,Paste,另存新设计：TeeMagic.3.CreatetheModelCreatetheSeptum：DrawaBox(Septum):basecorner(-0.45in,offset-0.05in,0in)Dx=0.45in,Dy=0.1in,Dz=0.4inSubtracttheSeptumfromtheT-Junction:Modeler->Boolean->Subtract4.AssignWavePortsWavePort1:Selectface:yzplaneatx=2Modeler->AssignExcitation->WavePortWavePort2:(Port2)WavePort3:(Port3)5.SetUpandGenerateSolutionsAddSolutionSetup:

10GHzintheSolutionFrequency.AddFrequencySweeptotheSolutionSetup:AddSweep,Interpolating,Start=8GHz,Stop=10GHz,StepSize=0.01GHzValidatetheDesign.AnalyzetheDesign.6.MovethePositionoftheSeptum1.Right-clickthedesignTeeModel2.clickDesignProperties.3.UndertheLocalVariablestab,selectValue.4.Type0.2intheValuetextboxforthevariableoffset.5.Re-analyzetheDesign7.Results7.Results3.3波导T接头的优化1.UsingOptimetricswithHFSSOptimetricsenablesyoutodeterminethebestdesignvariationamongadesign’spossiblevariations.Parametric:

Defineoneormorevariablesweepdefinitions,

HFSSsolvesthedesignateachvariation.Optimization:

Identifythecostfunctionandoptimizationgoal.Optimetricschangesparametertomeetthatgoal.Sensitivity:

Optimetricsdeterminethesensitivityofthedesigntosmallchangesinvariables.Tuning:

Variablevaluesarechangedinteractivelyandtheperformanceofthedesignismonitored.Statistical:

Optimetricsdeterminesthedistribution,causedbystatisticaldistributionofvariablevalues.3.3波导T接头的优化2.T优化优化要求：波导尺寸：a=0.9in,b=0.4in隔片尺寸：width=0.45in,thick=0.1in频率范围:10GHz优化参数：offset优化目标：|S31|2=2*|S21|22.SetuptheOptimetricsDesignSavetheTeeProjectUnderaNewName:OptimTeeDeletetheFrequencySweep:WillspecifyintheSolutionSetupdialogbox,10GHz.3.SetupandSolvethe

ParametricAnalysisAddaParametricSetup:Right-clickOptimetricsintheprojecttree,ClickAdd>Parametricontheshortcutmenu.3.SetupandSolvethe

ParametricAnalysisAddaVariableSweepDefinition:AddVariable:offsetStart:0in,Stop:1in,Step:0.1inAdd>>3.SetupandSolvethe

ParametricAnalysisSaveFieldsandMeshforEverySolvedDesignVariationOptionstab,selectSaveFieldsAndMesh.3.SetupandSolvethe

ParametricAnalysisSpecifytheSolutionQuantitiestoEvaluate:powerquantitiesatPort1,Port2,andPort3,|Si1|2Calculationstab->SetupCalculations.3.SetupandSolvethe

ParametricAnalysisOutputVariables->Power11=mag(S(Port1,Port1))*mag(S(Port1,Port1))Power21=mag(S(Port1,Port1))*mag(S(Port1,Port1))Power31=mag(S(Port3,Port1))*mag(S(Port3,Port1))3.SetupandSolvethe

ParametricAnalysisSelectPower11,Power21,Power31ClickAddCalculation3.SetupandSolvethe

ParametricAnalysisSolvetheParametricAnalysis:Right-clickParametricSetup1,andthenclickAnalyze.4.ReviewtheParametricResultsPlotofS-ParameterResultsvs.offsetPosition:Asseptumoffset<0.3in,thetransmissiondecreasesatPort2andincreasesatPort3.Asseptumoffset>0.3in,itbecomeslesseffective,reflectionincreasesattheinputport,Port1.maximumvaluefortheoptimizationtobe0.3inches.4.ReviewtheParametricResultsPlotofPowerDistributionvs.OffsetPositionoffset=0in,P3/P2=1:1;offset=0.1in,P3/P2~2:1;offset=0.3in,P3/P2~9:1;ThegoalforoptimizationisPower31=2*Power21,startingvaluetobe0.1inches.4.ReviewtheParametricResultsAnimatetheFieldOverlayPlot:Offset=0inOffset=0.2inOffset=0.4inOffset=0.8in5.SetupandSolvetheOptimizationAnalysisYouwillcompletethefollowingtasks:Setupthevariable

offsetforanoptimizationanalysis.Addanoptimizationsetuptotheproject.Addacostfunctiontotheoptimizationsetup.Solvetheoptimizationanalysis.5.SetupandSolvetheOptimizationAnalysisSelecttheVariabletobeOptimized:HFSS->DesignPropertiesSelectOptimization,variableoffset,selectInclude,5.SetupandSolvetheOptimizationAnalysisAddanOptimizationSetup:HFSS->OptimetricsAnalysis->AddOptimizationClickQuasiNewton,Max.No.ofIterationsis10005.SetupandSolvetheOptimizationAnalysisAddaCostFunction:SetupCalculations->Cal.Expr.=Power31-2*Power21Goal->0,Weight->1,AcceptableCost->0.0015.SetupandSolvetheOptimizationAnalysisModifytheVariable’sStartingValue:ClicktheVariables

tab.StartingValue->0.1,Min->0,Max->0.3SolvetheParametricSetupBeforetheOptimization:Optimizationusestheresultstodeterminethestartingvalue.Generaltab->ClickParametricSetup1->SelectSolvetheparametricsweepbeforeoptimization.SelectUpdatedesignparametervaluesafteroptimization.SolvetheOptimizationAnalysis6.ReviewtheOptimizationResultsViewtheCostvs.SolvedIterationOptimizationSetup1->ViewAnalysisResult->PostAnalysis->Result6.ReviewtheOptimi