CST-STUDIO-SUITE-2014離散端口概述

Beside

waveguideports

or

planewaves

,thediscreteportsoffersanotherpossibilitytofeedthecalculationdomainwithpower、Twomainporttypesareavailable:thediscreteedgeandthediscretefaceport、Theyaredividedinthreedifferentsubtypes,consideringtheexcitationasavoltageorcurrentsourceorasanimpedanceelementthatalsoabsorbspowerandenablesSparametercalculation、

Discreteportsaremainlyusedtosimulatelumpedelementsourcesinsidethecalculationdomain、Theseportsareagoodapproximationforthesourceinthefeedingpointofantennaswhencalculatingfarfields、Insomecases,theseportsmayalsobeusedtoterminatecoaxialcablesormicrostriplines、However,duetothetransmissionbetweentransmissionlinesofdifferentgeometricdimensions,reflectionsmayoccurthataremuchlargerthanthosefortheterminationwithwaveguideports、Forlowerfrequencies(paredtothedimensionofthediscreteport),thesereflectionsmaybesufficientlysmall,suchthatthesekindsofportsmayalsobeusedsuccessfullyfortheSparametercalculationsofmultipinconnectors、

Pleasenotethattheinputsignalfortheportis

normalized

dependingonthechosenporttype、

Contents

DiscreteEdgePorts

GeneralDescription

Construction

PortTypes

MeshRepresentation

SymmetryPlanes

DiscreteFacePorts

GeneralDescription

Construction

PortTypes

Seealso

DiscreteEdgePorts

GeneralDescription

Althoughthewaveguideportsarethemostaccuratewaytoterminateawaveguide,discreteedgeportsaresometimesmoreconvenienttouse、Discreteedgeportshavetwopinswithwhichtheycanbeconnectedtothestructure、

Thiskindofportisoftenusedasfeedingpointsourceforantennasorastheterminationoftransmissionlinesatverylowfrequencies、Athigherfrequencies(e、g、thelengthofthediscreteportislongerthanatenthofawavelength)theSparametersmaydifferfromthosewhenusingwaveguideportsbecauseoftheimpropermatchbetweentheportandthestructure、

Construction

Adiscreteedgeportconsistsofaperfectconductingwireconnectingstartandendpointsandalumpedelementinthecenterofthewire、

Thetypicalwaytodefineadiscreteportistopickitstwoendpointsfromthestructureusingthemonpicktoolsandthentoenterthediscreteportdialogbox:

Discreteportscanbeappliedtodifferenttypesofportstructuresaspresentedbelow:

Coaxialport

Microstripport

Coplanarport

Note:TheSParameterportsarethemostfrequentlyusedPortTypesandcontaininternalresistorsforcalculatingSParameterswithfixedreferenceimpedances、Incontrast,theVoltageandCurrentportsareidealsources、ThelattertypesofportsarenormallyusedforEMCtypesofapplication、

PortTypes

Voltageport:Thisporttyperealizesavoltagesource,excitingwithaconstantvoltageamplitude、Ifthisportisnotstimulatedinthetransientanalysis,thevoltagealongthewireissettozero、Thevoltageexcitationsignalwillberecordedduringthesolverrun、

Currentport:Thisporttyperealizesacurrentsource,excitingwithaconstantcurrentamplitude、Thecurrentexcitationsignalwillberecordedduringthesolverrun、

Impedanceelement(SParametertype):Thisporttypeismodeledbyalumpedelement,consistingofacurrentsourcewithaninnerimpedancethatexcitesandabsorbspower、Thecurrentsourcewillonlybeactivewhenthediscreteelementisthestimulationportinthetransientanalysis、Thisportrealizesaninputpowerof1WandenablesthecalculationofcorrespondentSparameter,basedontheiningandoutgoingtimesignals、Inaddition,itisalsopossibletomonitorthevoltageacrossandthecurrentthroughthediscreteport、NotethattheorientationofthediscreteportisusedtodeterminethephaseoftheSparameters、

MeshRepresentation

Thediscreteportisdefinedbytwopoints,determinedeitherbypickingtwopointsorenteringvalid

expressions

forthepoint’scoordinates、

Theinputdatacanbeseeninthe

ModelerView

,wherethediscreteportisrepresentedbyastraightlineandacone、Duetothefactthatdiscreteelementsmustbelocatedonthecalculationmesh,itisalwaysadvisabletoexaminethemeshrepresentationoftheelementinthe

MeshView

、Here,onecanobservethatalmostallelementsonthegridconsistofametallicwire、Onlythemiddleelementcontainsthesource、

Meshrepresentationofadiscreteelement,consistingoftwometallicwires(markedinorange)andasourceelement(redcone)、Thecolorsofthewireandtheconecanbechangedinthe

ColorsViewOptions

dialog、

SymmetryPlanes

Ifadiscreteporttouchesasymmetryplane,anelectricplanemustbechoseninthecaseofaperpendicularcutandamagneticplanemustbechoseninthecaseofaparallelallocation、Thecorrespondingsymmetryfactorsforthediscreteelementswillbeconsideredautomatically,suchthatthesimulationresults(dependingonimpedanceandinputpower)willnotbechangedbythedefinitionofsymmetryplanes、However,itshouldbementionedthatifanelectricsymmetryplanehasbeendefined,thesymmetryformulationvariesslightlyfromtheoriginalproblemregardingtheelement'sallocation、Asyoucanseeinthepicturebelow,thesymmetricrepresentationofasourcedirectlyatthesymmetryplaneisequivalenttoadiscreteelementwithtwosourcesinthemiddle、Concerningthesimulationresults,thiseffectusuallyisnegligibleandcanbeignored、

DiscreteFacePorts

GeneralDescription

Thediscretefaceportisaspecialkindofdiscreteport、Itissupportedbytheintegralequationsolver,thetransientsolver,aswellasthefrequencydomainsolverwithtetrahedralmesh、Thediscretefaceportisreplacedbya

DiscreteEdgePort

ifanyothersolverischosen、Twodifferenttypesofdiscretefaceportsareavailable,consideringtheexcitationasavoltageorasanimpedanceelementwhichalsoabsorbssomepowerandenablesSparametercalculation、

Construction

Afaceportcanbedefinedbypickingtwoseparateedges(

PickEdgeMode

)andchoosing

Simulation:

SourcesandLoadsDiscretePort、Furtheradiscretefaceportcanbecreatedbetweentwo

edgechains

、

Asurfacewillbecreatedbetweenanedgechainandasurface(

PickFaceMode

)ifoneedgechainandonesurfaceispicked、

Thefaceportwillbecreatedbetweenthetwoselectededges、

Picktwoedgechains,thenadddiscreteport、

Pickanedgeoranedgechain

andaface,thenadddiscreteport、

Bydefaulttheexcitationtakesplaceatthe(highlightedred)centeredgeoftheport、Aclassicaldiscreteportisalsodisplayed、Itwillbeusedifanothersolverisusedforsimulation

ThecreatedsurfaceisaPECsheetandwillbemeshed、

PortTypes

Voltageport:Thisporttyperealizesavoltagesource,excitingwithaconstantvoltageamplitude、Ifthisportisnotstimulatedinthetransientanalysis,thevoltagealongthewireissettozero、Thevoltageexcitationsignalwillberecordedduringthesolverrun、

Impeda