CH3 無源器件的設(shè)計(jì)仿真與優(yōu)化

電磁工程設(shè)計(jì)與仿真第三章微波無源器件

設(shè)計(jì)、仿真與優(yōu)化主要內(nèi)容3.2波導(dǎo)T接頭的仿真3.1波導(dǎo)T接頭的原理3.3波導(dǎo)T接頭的優(yōu)化3.4波導(dǎo)魔T的仿真3.1波導(dǎo)T接頭的原理一、功分器的基本特性功率分配器（功分器）是無源三端口器件.特性：所有端口都匹配的三端口無耗互易網(wǎng)絡(luò)是不可能的。三個(gè)條件任意一個(gè)條件放寬，則可以實(shí)現(xiàn):若三端口網(wǎng)絡(luò)非互易，則所有端口可匹配，并無耗。若無耗互易的三端口網(wǎng)絡(luò)只有兩個(gè)端口匹配，可實(shí)現(xiàn)。若三端口網(wǎng)絡(luò)有耗，則該網(wǎng)絡(luò)互易，全部端口可匹配。二、波導(dǎo)H-T，E-T3臂：H壁1,2臂:平分臂分支在主波導(dǎo)TE10磁場(H)平面內(nèi)，因此稱H-T1.波導(dǎo)H-T功率分配功能：1233臂自身有反射，若在該分支波導(dǎo)加入匹配裝置，可使3臂匹配，入射功率全部從1、2臂平分輸出。3臂輸入時(shí)，從1/2臂等幅、同相輸出；1.波導(dǎo)H-T應(yīng)用：波導(dǎo)功率分配網(wǎng)絡(luò)1臂輸入時(shí)，2、3臂輸出；1、2臂不隔離。2臂輸入時(shí)，1、3臂輸出；1、2臂不隔離。1231231.波導(dǎo)H-T問題：1,2不隔離有何影響？求和功能：123信號1信號2信號1＋信號2兩信號分別從1、2臂輸入，且到達(dá)分支波導(dǎo)中軸T面時(shí)相位相同，則3臂輸出兩信號之和，稱為和信號。T1.波導(dǎo)H-T求差功能：123信號1信號2信號1－信號2兩信號分別從1、2臂輸入，且到達(dá)分支波導(dǎo)中軸T面時(shí)相位相反，則3臂輸出兩信號之差，稱為差信號。

若此時(shí)兩信號等幅，則3臂無輸出；T1.波導(dǎo)H-T2.波導(dǎo)E-T21,2：平分臂3：E臂分支在主波導(dǎo)TE10電場(E)平面內(nèi)，因此稱E-T功率分配功能：2133臂自身有反射，但若在該臂加入匹配裝置，可使3臂匹配，入射能量全部從1、2臂平分輸出。3臂輸入時(shí)，從1、2臂等幅、反相輸出；2.波導(dǎo)E-T1臂輸入時(shí)，2、3臂輸出；1、2臂不隔離。1231232臂輸入時(shí)，1、3臂輸出；1、2臂不隔離。2.波導(dǎo)E-T求差功能：123兩信號分別從1、2臂輸入，且到達(dá)分支波導(dǎo)中軸T面時(shí)相位相同，則3臂輸出兩信號之差，稱為差信號。信號1－信號2信號1信號2

若兩輸入信號等幅，則3臂無輸出。T2.波導(dǎo)E-T求和功能：兩信號分別從1、2臂輸入，且到達(dá)分支波導(dǎo)中軸T面時(shí)相位相反，則3臂輸出兩信號之和，稱為和信號。123信號1＋信號2信號1信號2T2.波導(dǎo)E-T3.T接頭匹配波導(dǎo)T等效模型：T形結(jié)并聯(lián)導(dǎo)納：忽略B=0，且Z1=Z2=Z0,輸入不匹配。3.波導(dǎo)H-T匹配3臂匹配方法：隔片匹配切角匹配銷釘匹配根據(jù)三端口特性：由于H-T互易無耗，當(dāng)3臂匹配時(shí)，1,2臂肯定不匹配。三.雙T和魔T(1)雙T根據(jù)E-T，H-T特性，雙T特性：①輸入：②③等幅同相輸出，

④隔離；④輸入：②③等幅反相輸出，

①隔離；②③輸入：①輸出和信號，

④輸出差信號；“①④臂隔離”原因：243T4臂輸入的TE10模式關(guān)于中軸面T反對稱，而1臂中TE10模式關(guān)于中軸面T對稱，故相互不能激勵(lì)。1臂（4臂）輸入的TE10?？梢栽?臂（1臂）中激勵(lì)起高次模，但高次模式不能傳輸，不能輸出。4輸入，1隔離243T1輸入，4隔離(1)雙T(2)魔T234（E）1（H）調(diào)配裝置魔T=匹配雙T(3)隔離性：①④隔離；②③隔離；

主要特性：匹配性：每個(gè)端口匹配；①④匹配，②③自動(dòng)匹配；(2)平分性：

①輸入：②③等幅同相輸出;

④輸入：②③等幅反相輸出;②③輸入：④=差，①=和;單脈沖雷達(dá)和差網(wǎng)絡(luò)：ΣΔΣΔΣΣΔ(3)魔T的應(yīng)用和波束差波束俯仰差和激勵(lì)方位差測角功能(3)魔T的應(yīng)用ΣΔΣΔ3.2波導(dǎo)T接頭的仿真1.T接頭仿真要求：波導(dǎo)尺寸：a=0.90in,b=0.4in隔片尺寸：W=0.45in,t=0.1in,offset=0or0.2in頻率范圍:8-10GHz分析端口反射和功率分配情況，為優(yōu)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將T接頭Copy,Paste,另存新設(shè)計(jì)：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波導(dǎo)T接頭的優(yōu)化1.UsingOptimetricswithHFSSOptimetricsenablesyoutodeterminethebestdesignvariationamongadesign’spossiblevariations.Parametric:

Defineoneormorevariablesweepdefinitions,

HFSSsolvesthedesignateachvariation.Optimization:

Identifythecostfunctionandoptimizationgoal.Optimetricschangesparametertomeetthatgoal.Sensitivity:

Optimetricsdeterminethesensitivityofthedesigntosmallchangesinvariables.Tuning:

Variablevaluesarechangedinteractivelyandtheperformanceofthedesignismonitored.Statistical:

Optimetricsdeterminesthedistribution,causedbystatisticaldistributionofvariablevalues.3.3波導(dǎo)T接頭的優(yōu)化2.T優(yōu)化優(yōu)化要求：波導(dǎo)尺寸：a=0.9in,b=0.4in隔片尺寸：width=0.45in,thick=0.1in頻率范圍:10GHz優(yōu)化參數(shù)：offset優(yōu)化目標(biāo)：|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