lab 1: circuit simulation fundamentals · 7. launch the simulation and display the data. a. at the...
TRANSCRIPT
ADS Fundamentals – 2009
LAB 1: Circuit Simulation Fundamentals Overview‐Thislabcoversuserinterfacebasics,ADSfiles,schematiccapture,simulation,anddatadisplay.Inaddition,tuningandADSexamplefilesarealsocovered.
OBJECTIVES • Createanewprojectandschematicdesigns
• SetupandperformS‐parametersimulation
• Displaysimulationdataandsavefiles
• Tunecircuitparametersduringsimulation
• UsetheExamplesfilesandnodenames
• PerformaHarmonicBalancesimulation
• Writeanequationinthedatadisplay
©CopyrightAgilentTechnologies2009
Lab 1: Circuit Simulation Fundamentals
1‐2 ©CopyrightAgilentTechnologies2009
Table of Contents
1. Start ADS on the computer. .................................................................................3
2. Examine the Main Window preferences...............................................................4
3. Create a new Project............................................................................................5
4. Examine the files in your new project directory. ...................................................6
5. Create a low-pass filter design. ............................................................................6
6. Setup the S-Parameter Simulation.....................................................................11
7. Launch the simulation and display the data. ......................................................11
8. Save the Data Display Window..........................................................................13
9. Tune the filter circuit. ..........................................................................................14
10. Copy an RFIC Harmonic Balance example. ......................................................17
11. Add a wire label (node name) and simulate. .....................................................19
12. Plot the spectrum of Vout in dBm. ....................................................................20
13. Examine the Main Window again .....................................................................22
Lab 1: Circuit Simulation Fundamentals
1‐3©CopyrightAgilentTechnologies2009
PROCEDURE
1. StartADSonthecomputer.
a. ForPCs:ClicktheshortcuticonforADSifitappearsonyourscreen,orusetheStart>ProgramscommandtofindandstartAdvancedDesignsSystemasshownhere.ForUNIX:typethescript/commandattheterminalprompt(forexample:hpads).
b. WhentheMainWindowappears,youshouldalsoseetheGettingStarteddialog.Ifitappears,closeit–youwilllearnhowtodoallofthethingsitasksandmuchmore…ifitdoesnotappear,ithasalreadybeenturnedoff.Also,donotbeconcernedabouttheFileView–itwilldependuponwhichdirectorystart‐updirectoryADSisusing.
NOTE:yourFileViewmaybedifferent,dependinguponwhereADSisstarted…
Lab 1: Circuit Simulation Fundamentals
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2. ExaminetheMainWindowpreferences.
a. IntheMainWindow,clickTools>Preferences.
b. WhentheMainPreferencedialogappears,besurethattherearenocheckedboxesforthedisplaygreetingortheschematicwizard.Youwillnotneedtheminthiscourse.
c. BesuretheLargeToolbarBitmapischecked(turnedon)andleavetheothersettingsasshownintheirdefaultcondition.
MostADSwindowshaveapreferencedialogsothatyoucansetorcustomizethewindowasdesired.Youcantryalloftheseafterthiscourse.
d. ClickOKtodismissthedialog.
BesuretheseareturnedOFFasshownhere.
Lab 1: Circuit Simulation Fundamentals
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3. CreateanewProject.
ForthisstepyouwillusetheiconsontheMainwindow.Usingiconstoexecutecommandsusuallyrequiresfewermouseclicks.Youcanidentifywhatanicondoesbyplacingthecursorontheicontodisplayatextbox:thisiscalledballoonhelp.
a. IntheMainwindow,selecttheFileViewtabandthenclicktheicon:ViewStartupDirectory.ThiswillshowthatyouareinthedefaultstartingdirectoryforADSprojects.
b. Click:File>NewProjectorusethetheicon.Whenthedialogboxappears,appears,youwillseethedefaultworkingworkingdirectory.OnyourowncomputeritwillbeC:\users\defaultbutC:\users\defaultbutinanADSclassroomitmaybedifferent(C:\users\ads)socheckwiththeinstructor.Insertthecursorattheendofendofthelineandtypethename:lab1.lab1.
NoteonProjectTechnologyFiles‐TheADSStandardLengthunitisusedinlayout.IfyouhadaDesignKit(foundrykitorPDK)installed,youcouldselectitherefromthedrop‐downlist(arrowbutton).Forthislabusethedefaultvalue(mil)asshown.
c. ClickOKandtheprojectiscreatedandaschematicwindowopens,readyforyoutocreateadesign.
CreateaNewProject
ViewStartupDirectory
Lab 1: Circuit Simulation Fundamentals
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4. Examinethefilesinyournewprojectdirectory.
a. LookattheMainwindowFileViewtab.Itshouldnowshownowshowallthefilesthatareautomaticallybuiltinthethelab1projectdirectory.Noticethatthesub‐directoriesdirectories(data,networks,etc.)werealsocreatedautomatically,readyforyoutocreatedesigns,simulateandsimulateandplotdata.
b. LookintheProjectViewtabandnoticethattheprojectisprojectisemptyatthistime–noschematicsordata
displaysyet.
c. Also,noticethattheschematic,layout,anddatadisplayiconsarenowactivated(notgray).Thismeansyoucannowopenthosewindowswhichyouwilldointhenextsteps.
5. Createalowpassfilterdesign.
a. IntheMainwindow,clicktheNewSchematicWindowicon(shownhere).Thisisthesameasselectingthemenucommand:Window>NewSchematicWindow.Immediately,theSchematicwindowwillappear.Ifyourpreferencesaresettocreateaninitialschematic,youwillhavetwoschematicsnowopened–closeeitheroneofthem.
ComponentPaletteandscrollbar
Messages,X‐Ylocationorcursor,andotherinformation.
Lab 1: Circuit Simulation Fundamentals
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Lab 1: Circuit Simulation Fundamentals
1‐8 ©CopyrightAgilentTechnologies2009
ComponentHistoryList
ComponentPaletteListdeterminestheitemsavailableonthepalette.
b. Savetheschematic.Noticethetopwindowborderoftheschematicshowstheschematicnameasuntitled.Clicktheicon(shownhere)andtheSaveDesignAsdialogwillappear.TypeinthenamelpfandclickSave.Thiswillsaveitinthenetworksdirectoryoflab1project.
NOTEonsavingdesignsAfternamingtheschematic,theSaveiconwillnotbringupthissamedialogbox.Instead,itwillsavethenameddesign.Tosavethedesignwithadifferentname,usethecommand:File>SaveDesignAs.
c. Examinetheschematicwindowcommandsandicons.andicons.ClickthesmallsmallarrowontheComponentComponentPalettelisttoseetoseethepalettechoices.Also,choices.Also,movetheScrollScrollBardownanduptoseetoseehowitworks.
d. IntheLumpedComponentspalette,select(click)thecapacitorC shownhere(nottheCmodel).ThenclicktheRotateByIncrementiconasneededforthecorrectorientationandthenclicktoinsertthecapacitorasshownontheschematic.Next,insertanothercapacitor.
NOTEonschematics:youcanchangethecoloroftheschematicbackground,griddots,andmoreusingOptions>Preferences.Thiswillbecoveredlaterinthecourse.
RotateCursorwithcrosshairs=commandisactive.
NOTE:someboxedicons(R,LandC)aremodels–notcomponents.
Lab 1: Circuit Simulation Fundamentals
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Lab 1: Circuit Simulation Fundamentals
1‐10 ©CopyrightAgilentTechnologies2009
e. Continuecreatingthelow‐passfilterasshownbyinsertingtheinductorandgrounds(iconsareshownhere).Thenwirethecomponentstogether.Thiswillgiveyoupracticewithschematiccapture.Youcantryusingthecopy,moveandothericonsorcommands.
f. Afterthefilterisbuilt,editthevalueofC2tobe3pico‐farads.Todothis,doubleclickthecapacitorsymbolorselectthecapacitorandusetheicon(R=17shownhere).Whenthedialogboxappears–changethevalue:C=3.0pF,clickApplyandOK.
g. Next,selecttheSimulationS_ParampaletteandinserttheSparametersimulationcontroller(gearicon).UsetheESCkeytoendthecommand.
h. Inserttheportterminations:TermNum=1andTermnum=2.
i. UseComponentHistory:Afterthecircuitisbuilt,deletecapacitorC2andthenreinsertitbytypingorselecting(history)thecapitalletterCintheComponentHistoryfieldandpressEnter.Next,editthevaluedirectlyontheschematicbyhighlightingthevalueandtypingoveritwiththevalue(3.0pF).Verifythatithaschangedbylookingatthevalueintheeditdialogbox.
COMPONENTHISTORY:Youcaninsertcomponentsiftheyhavebeeninsertedpreviously,orbytypinginthecomponentname(C,L,Retc)insteadofusingthepalette.
Lab 1: Circuit Simulation Fundamentals
1‐11©CopyrightAgilentTechnologies2009
6. SetuptheSParameterSimulation.
a. Tosetupthesimulation,doubleclickontheS‐S‐parametersimulationcontrollerontheschematic.schematic.Whenthedialogboxappears,changethechangetheStepsizeto0.5GHzandclickApply.Apply.Noticehowitupdatesthevalueonthethescreen.TheOKbuttondoesthesamethingasthingasApplyandalsodismissesthedialogbox–box–donotclickOKyet.
b. ClicktheDisplaytabandyouwillseethattheStart,theStart,StopandStepvalueshavebeencheckedchecked(bydefault)tobedisplayedontheschematic.Laterinthiscourse,youwillusethethedisplaytabtocheckotherparametersyouwantyouwantdisplayedontheschematic.
c. ClicktheOKbuttontodismissthedialogbox.Youbox.Youarenowreadytosimulate.
7. Launchthesimulationanddisplaythedata.
a. Atthetopoftheschematicwindow,clicktheSimulateicongear(shownhere)tostartthesimulationprocess.
b. Next,lookfortheStatuswindowtoappearandyoushouldseemessagessimilartotheoneshere,describingtheresultsofthesimulation,thewritingofthedatasetfile,andthecreationofadisplaywindow.Ifnot,asktheinstructorforhelp.
Ifnosimulationerrorsoccurred,closetheStatuswindow.Youcanalwaysrecallthestatuswindowusingtheschematicwindowcommand:Window>SimulationStatus(tryit).
NOTE:Ifyouscrollup,youwillseemoresimulationinformation.
Lab 1: Circuit Simulation Fundamentals
1‐12 ©CopyrightAgilentTechnologies2009
c. TheDataDisplaywindowwillappearwiththenamelpfinthetopleftcorner–thisisthesamenameasyourschematic.Also,youarelookingatpage1whichisblankatthistime.Examinethepicturebelow‐thenextstepswillshowhowtodisplaythesimulationdata.
d. Tocreatetheplot,clickontheRectangularPloticonandmovethecursor(outlinedbox)intothewindowandclick.Whenthenextdialogboxappears,selecttheS(2,1)dataandclicktheAddbutton.ThenselectdBastheformatforthedata.ClickOKinbothboxes.
*
NOTE:Anasterisknexttoawindowname(lpf*)meansitisnotsaved.
ThedefaultDATASETname(lpf)appearshere.
Thispaletteiswhereyouchooseaplottype,list,table,orequationtoinsert.
Scrollbuttonsforlistsofdata.
Rectangularplot
Markericonbuttons.
Lab 1: Circuit Simulation Fundamentals
1‐13©CopyrightAgilentTechnologies2009
Theplotshouldshowareasonablelowpassfilterresponse.Also,ifyouhaveamousewheel–tryusingittozoominandout.
e. Putamarkeronthetrace:Clicknewmarkericononicononthetoolbar(shownhere).Youwillbepromptedtoselectatracetoinsertthemarker.Next,Next,tryusingtheothermarkericons.Youcanalsoalsomoveitusingthecursororthekeyboardarrowarrowkeys.Trydeletingthemarkerorputtinganothermarkeronthe
trace.
8. SavetheDataDisplayWindow.
a. Savethisdatadisplaywindow:UsetheFile>SaveAscommandandusethenextdialogboxtosaveitwiththedefaultnamelpf.Thismeansthatitwillbesavedasa.ddsfile(datadisplayserver)intheprojectdirectoryanditwillhaveaccesstoalldata(.dsfilesordatasets)inthedatadirectory.Thisstepshowsyouthatdatadisplaywindowsaresavedintheprojectdirectoryandnotinthedatadirectory.Onlydata(datasets)arestoredinthedatadirectory.
Lab 1: Circuit Simulation Fundamentals
1‐14 ©CopyrightAgilentTechnologies2009
b. Closethedatadisplaywindowusing:File>Close.
c. Re‐openthesaveddatadisplaybyclickingtheDataDisplayicon(shownhere)fromtheSchematicorMainwindow.Afterthewindowopens,clicktheOpeniconfolder(shownhere).Selectlpf.ddsinthedialogandclickOpen.ItwillreappearwithyourS21plot.Also,noticethatthedefaultdatasetname(lpf)remainsfromyourprevioussimulation.KEEPTHISWINDOWOPENforthenextsteps.
9. Tunethefiltercircuit.
ThisstepintroducestheADStuningfeaturethatallowsyoutotuneparametervaluesofcomponentsandseethesimulationresultsinthedatadisplay.Inthisstep,youfirstselectthecomponentsandthenselectthetuningfeature.Ifyouselectthetuningfeaturefirst,youmustselectthecomponentparametersandnotthecomponents.
a. PositiontheDataDisplayandtheSchematicwindowssoyoucanseethembothonthescreen.Ifnecessary,re‐sizethewindowsanduseViewAll.
b. Now,startthetunerbyclickingthecommand:Simulate>TuningorclicktheTuneParametersicon(shownhere).
ViewAll
TuneParameters
DataDisplayicon:
OpenanexistingDataDisplay
Lab 1: Circuit Simulation Fundamentals
1‐15©CopyrightAgilentTechnologies2009
c. Immediately,thestatus(simulation)windowwillappearalongwiththeTuneControldialogbox(shownhere).GoaheadandclickontheCparameterfortheC1capacitorasshownhere.Whenyoudo,thetunableparameterwillappearintheTunecontrollerandtheparameterwillappearwith{t}toshowthatitisenabledfortuning.Anotherwaytoselecttheparameterisnext.
d. Clickontheinductorsymbolandwhenthesmalldialogappears,clickontheLandOK.Thiswilladdtheinductorinthetunecontroller.
Lab 1: Circuit Simulation Fundamentals
1‐16 ©CopyrightAgilentTechnologies2009
e. ArrangeyouDataDisplaywindowwiththeS‐21plotsothatyoucanseeitalongwiththeTuner.Placeamarkeronthe5GHzdatapointasshownhere.Thentrymovingthetunerslidersandseehowthetraceisautomaticallyupdatedasifyouweretuningwithaninstrument.Youcanalsotrytypinginthevalueorchangethewaythesliderisused.
f. IncreasetheMaxvaluesto6forbothparametersandcontinuetuningtogetatypicallow‐passfilterresponse:about‐3dBnear2GHz,asshownhere‐movethemarkerto2GHztoseethis.
g. StorethetracebyclickingontheStorebuttonandOKasshownhere.Thenmovethetuningslidersagain‐thestoredtraceremains(dashedline)whilethenewtracerespondstothetuning.Tracescanbestored/recalledandmadevisibleasneeded.Goaheadandtrytheseandotherstobetterunderstandhowthetunerworks.
h. UsetheClosebuttononthetunertocloseit.ThenSavethedatadisplayandtheschematicusingtheSaveicon(inbothwindows)shownhere.Finally,closeallthewindows,excepttheADSMainwindow.Next,youwilluseHarmonicBalancewithanADSexample.
Lab 1: Circuit Simulation Fundamentals
1‐17©CopyrightAgilentTechnologies2009
IMPORTANTNOTE:UsingADSExamples
AlloftheexamplesshippedwithADScanbeexaminedinthe
theExamplesdirectory.However,tousethemforyourdesigndesignwork,youmustcopythefilesintoanotherdirectory.InIngeneral,theexamplesdirectoryisread–onlyandthefilesmustmustremainunchanged.Thefollowingstepswillgiveyousomesomeexperienceleveragingexamplesforyourownuse.
10. CopyanRFICHarmonicBalanceexample.
a. GototheADSMainwindow,FileViewtab,andclickontheViewExampleDirectoryicontoseethelistofexampletopicsbutdonotgoanyfurther,simplylookatthechoices.Afterward,clickontheViewCurrentWorkingDirectoryicontoseethatyouarestillinthelab1project.
b. Youaregoingtocopyaschematicdesignfromoneoftheexampledirectoriesintothelab1project(networks).IntheADSMainwindow,clickFile>CopyDesignandtheCopyDesigndialogwillappear.
c. Select:FromDesign:Thisiswhereyougettheexampledesign.Whenthedialogappears,selectExampleDirectoryandBrowse.Thenusethedialogboxes,doubleclickingonRFIC>amplifier_prj>networks>HBtest.dsnandOpen.
d. SpecifytheToPath:SelectWorkingDirectory,whichshouldbethenetworksdirectoryofthelab_1project(shownhere).Alsocheckthebox:CopyDesignHierarchy.ClickOKandacopyoftheHBtestanditshierarchy(sub‐circuits)willbecopiedintoyourlab1_project.
Lab 1: Circuit Simulation Fundamentals
1‐18 ©CopyrightAgilentTechnologies2009
e. Afterthecopyiscomplete,openaschematicwindowandusetheiconorFile>OpenDesigntoopentheHBtest.dsn.Asshownhere,thisisthetop‐levelhierarchyoftheHBtest.dsn.ThisiswheretheHarmonicBalancesimulationissetup.Toseetheamplifiersub‐circuitclickontheamplifiersymbolandthenclicktheicon:PushintoHierarchy.
f. Noticethatthesub‐circuithasseveralbiaseddeviceswiththemodeldescription(modelcard)shown.ClickthePopOutofHierarchytogobacktothetoplevelwherethesimulationissetup.
Lab 1: Circuit Simulation Fundamentals
1‐19©CopyrightAgilentTechnologies2009
g. Afteryoureturntotheupperlevel,examinetheHarmonicBalancecontrollerbydoubleclickingonitorbyselectingitandclickingtheediticon(shownhere).
h. TheHarmonicBalancecontrollerhasmanytabsforsettingupsimulationparameters.Thepurposeofthisstepistogetyouacquaintedwiththesimulationcontrollerandnottouseallthesettings.Lookthroughthetabs,donotmakeanychanges,andCancelwhenyouaredone.
11. Addawirelabel(nodename)andsimulate.
a. ClickontheNameicon(shownhere).Whenthedialogappears,typeinthenameVinandclickonthewireornodeattheinputtotheamplifier.ClickClosewhenfinished.TheschematicnowhasaVinandaVoutwirelabel.
b. ClicktheSimulatebutton.Whenthesimulationfinishes,thenodevoltagesatVinandVoutwillbeavailableintheDataDisplay.
EditComponent
Thesimulatorissettocalculate960MHzwith5harmonics(order).NoticethattheV_1Tonesource(schematic)frequencyisalso960MHz.
Lab 1: Circuit Simulation Fundamentals
1‐20 ©CopyrightAgilentTechnologies2009
12. PlotthespectrumofVoutindBm.
a. Whenthedatadisplaywindowopens,selecttheRectangularPlotandinsertit.Immediately,anotherdialogwillappearwhereyouselectVoutandclickAdd.Next,thedialogwillaskyoufortheformat:SpectrumindBm.ClickOKandOKagain,andtheplotwillappear.
b. Putamarkeronthefirsttonetoverifythatitis960MHz.
c. InsertanequationbyselectingtheEqniconandinsertingitonthedatadisplay.Immediately,anotherdialogwillappear.
Lab 1: Circuit Simulation Fundamentals
1‐21©CopyrightAgilentTechnologies2009
d. Writetheequationinthefieldwithamistakeinspellingthenodename.Forexample,writeavoltagegainequationas:Gain=Vout/Vn.ClickApplyandyouwillseehowtheerrorisrecognized.
e. CorrectthespellingtoVin,clickApplyagainandOK.Thecorrectequationwillappear.
NOTEondatadisplayequations:Iftheequationisredincolor,thenitisinvalid.
f. TolisttheequationvalueofGain,insertalistbyselectingtheListtheListicon.Whenthedialogappears,clickthearrowandscrollscrolldowntotheEquationslist.WhenitappearsselecttheGaintheGainequationandAdditandclickOK.
YoushouldseealistofGain:thecomplexvoltageforeachfrequencycalculatedbyyourequationandtheHarmonicBalancedata.Actually,thiscircuitreallyhasmorecurrentgainthanvoltagegain.
g. Closeallthewindows–donotsavethefilesinfilesinthislab.Youwillnotneedthislaboranyoranyofitsfilestocontinue.
Type:Vntoseeamistake.
Lab 1: Circuit Simulation Fundamentals
1‐22 ©CopyrightAgilentTechnologies2009
13. ExaminetheMainWindowagain
a. NoticethattheProjectViewtabinthemainmainwindownowshowsyoursaveddesignsanddesignsanddatadisplays.
b. Anydesignordatadisplaycanbeopenedbybydoubleclickingonanyofthem–tryitandandthenclosethemusingtheMainWindowWindowcommand:File>CloseAll.
ENDOFLABEXERCISE–ifyouhavetime,trytheExtraExercises.
EXTRAEXERCISES:dotheseonlyifyouhaveadditionaltime.Otherwise,youcandothemforpracticeaftercompletingthecourse.
1. Trysearchingforanexampleofacprusingtheexamplesearchicon.
2. GobacktotheHBtestsimulationandincreasetheOrderintheHarmonicBalancesimulatorto7.Simulateagainandnotewhathappens.Also,changethevalueofFreqto940andnotewhathappens–youcanlearnaboutsimulationerrorsfromthistypeofexercise.
3. WriteanotherequationfortheHBtestresults:
Gain_fund=Vout[1]/Vin[1]
Determinewhatthebracketedvalueof[1]isdoingintheequation.
4. GobacktotheLPFdesignandopenthedatadisplaypage.TrywritinganequationforthephaseofS21andthenplotit:
5. Examineanyotherexamplesthatareinterestingtoyou.