lab 1: circuit simulation fundamentalsrmh072000/site/software_and_links_files/1b_lab.… ·...

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


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…



2. ExaminetheMainWindowpreferences.

a. IntheMainWindow,clickTools>Preferences.

b. WhentheMainPreferencedialogappears,besurethattherearenocheckedboxesforthedisplaygreetingortheschematicwizard.Youwillnotneedtheminthiscourse.

c. BesuretheLargeToolbarBitmapischecked(turnedon)andleavetheothersettingsasshownintheirdefaultcondition.

MostADSwindowshaveapreferencedialogsothatyoucansetorcustomizethewindowasdesired.Youcantryalloftheseafterthiscourse.

d. ClickOKtodismissthedialog.

BesuretheseareturnedOFFasshownhere.



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



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.



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.



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.



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.



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.



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.



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



c. Immediately,thestatus(simulation)windowwillappearalongwiththeTuneControldialogbox(shownhere).GoaheadandclickontheCparameterfortheC1capacitorasshownhere.Whenyoudo,thetunableparameterwillappearintheTunecontrollerandtheparameterwillappearwith{t}toshowthatitisenabledfortuning.Anotherwaytoselecttheparameterisnext.

d. Clickontheinductorsymbolandwhenthesmalldialogappears,clickontheLandOK.Thiswilladdtheinductorinthetunecontroller.



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.



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.



e. Afterthecopyiscomplete,openaschematicwindowandusetheiconorFile>OpenDesigntoopentheHBtest.dsn.Asshownhere,thisisthetop‐levelhierarchyoftheHBtest.dsn.ThisiswheretheHarmonicBalancesimulationissetup.Toseetheamplifiersub‐circuitclickontheamplifiersymbolandthenclicktheicon:PushintoHierarchy.

f. Noticethatthesub‐circuithasseveralbiaseddeviceswiththemodeldescription(modelcard)shown.ClickthePopOutofHierarchytogobacktothetoplevelwherethesimulationissetup.



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.



12. PlotthespectrumofVoutindBm.

a. Whenthedatadisplaywindowopens,selecttheRectangularPlotandinsertit.Immediately,anotherdialogwillappearwhereyouselectVoutandclickAdd.Next,thedialogwillaskyoufortheformat:SpectrumindBm.ClickOKandOKagain,andtheplotwillappear.

b. Putamarkeronthefirsttonetoverifythatitis960MHz.

c. InsertanequationbyselectingtheEqniconandinsertingitonthedatadisplay.Immediately,anotherdialogwillappear.



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.



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.

lab 1: circuit simulation fundamentalsrmh072000/site/software_and_links_files/1b_lab.… ·...

Documents