NA及TDR教育训练资料.docx
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NA及TDR教育训练资料
NA及TDR教育训练资料
Excellentscienceandtechnology,highfrequencymeasurement,education,training
Themeofeducationandtraining
Basicconceptsofsignals
Meaningofparameters
Networkanalyzer（NA）profile
Timedomainreflectometry（TDR）Introduction
.
AbriefintroductiontothemeasurementmethodsofNA/andTDR
.
ComparisonofNAandTDR
GhiatekTechnologies
GoodYePolytronTechnologiesInc
Firstpage
Basicmodeofsignaltransmission:
1,Single,end（singleended）:
signal+groundwire
+
+
Analog（sinusoidal）:
Gdigital（FangBo）:
G
2,Common,mode（common/samemode）:
signal+signal（boththesame）
+
Analog（sinusoidal）:
+
Digital（FangBo）:
+
+
GG
3,Differential,mode（differential/differential）:
positivesignal
+negativesignals（opposite）
+
Analog（sinusoidal）:
Digital（FangBo）:
VG
VG
-
-
GhiatekTechnologies
GoodYe,PolytronTechnologiesInc,secondpages
Basicmodeofsignalreception:
1,Single,end（singleended）reception:
signalvoltage
=signallinevoltagegroundvoltage
S
Singleendedreceiver
Signal
=S-G=S（G=0）
G
Singleendedtransmission
2,Common,mode（samemode）reception:
signalvoltage=two,linevoltageplus/2-groundvoltage
S1
Signal
=（S1+S2）/2-G=S
Samemodereception
S2
（S1=S2=S,G=0）
G
Samemodetransmission
3,Differential,mode（differential）receive:
signalvoltage=two,signallinevoltagesubtraction
S1
VG
S2
Differentialreception
Signal
=S1-S2=S
（S1=,S/2,S2=,-S/2,VG=0）
Differentialtransmission
GhiatekTechnologies
GoodYe,PolytronTechnologiesInc,thirdpages
Basicmodeofsignalreception:
1,Singleend（singleended）transmission,differentialmodereceivingresults?
?
S
G
Differentialreceivesignal
And
Signal
=?
?
?
Singleendedtransmission
2,Commonmode（commonmode）transmission,differentialmodereceivingresults?
?
S1
S2
Differentialreception
Signal
=?
?
?
G
Samemodetransmission
3,Differentialmode（differential）transmissionmodewithareceivingresults?
?
S1
VG
Samemodereception
Signal
=?
?
?
S2
Differentialtransmission
GhiatekTechnologies
GoodYe,PolytronTechnologiesInc,fourthpages
Characteristicsofbasicsignals:
1,Single,end（singleended）
）:
Advantages:
simplesignalprocessing,lowwirecost
ExceptforCOAXIAL,highercost）
Disadvantages:
higherworkingvoltage,highfrequencyinterference（exceptforCOAXIAL,mostundisturbed）
2,Common,mode（CO/samemode）:
Essentially,analogtransmissionisusedtosimulatenoiseorasameasurementofwirebalancecharacteristics,
Thereisnoneedtotransmitsignalsingeneral
3,Differential,mode（differential/differential）:
Advantages:
lowvoltage,noisecancellationfunction（highfrequencyperformance/priceratio,optimum）
Disadvantages:
signalprocessingcostsarehigher
GhiatekTechnologies
GoodYe,PolytronTechnologiesInc,fifthpages
Highfrequencycharacteristicsofthebasiclineterminationstructure:
Open
1,Open（open/circuit）:
Features:
signaltotalreflection,withthesamephase
2,Short（shortcircuit）:
Characteristic:
signaltotalreflection,butopposite
Short
MatchingLoad
3,Matching,Load（matchingload）:
Characteristics:
signalcompleteabsorption（transmission）withoutreflection
4,Unmatching（incompletematch）:
Characteristics:
thesignalportionabsorbs（transmits）,partiallyreflects
UnmatchingLoad
GhiatekTechnologies
GoodYe,PolytronTechnologiesInc,sixthpages
Highfrequencycharacteristicsofthebasiclineterminationstructure:
V
Open.
I=0
IiV
Features:
signaltotalreflection,withthesamephase
V
V
I
V
IrVR
1,Open（open/circuit）:
2,Short（shortcircuit）:
Characteristic:
signaltotalreflection,butopposite
R,V,I,V,rI,iI,R,I,iI
VVV
=T==-0
IIiV
V
IrV,
I,V,R,V,R,V,iV
VV
-==+0
V
V
V
V
V
Short
V
V
R
V
GhiatekTechnologies
GoodYe,PolytronTechnologiesInc,seventhpages
Overviewofhighfrequencytransmissionofbasiclines
Theactuallinecannotbecompletelymatched,sothesignalistransmittedovertheline
Aseriesofpenetrating（absorption）andreflectedresults
receivingend
Transmittingend
defect
GhiatekTechnologies
GoodYe,PolytronTechnologiesInc,eighthpages
Excellentscienceandtechnology,highfrequencymeasurement,education,training
Themeofeducationandtraining
Basicconceptsofsignals
Meaningofparameters
Networkanalyzer（NA）profile
Timedomainreflectometry（TDR）Introduction
.
AbriefintroductiontothemeasurementmethodsofNA/andTDR
.
ComparisonofNAandTDR
GhiatekTechnologies
GoodYePolytronTechnologiesInc
Ninthpage
Meaningofparameter
Characteristicimpedance
CharacteristicImpedance,
Z）
Thetransmissionlineisaffectedbyitsstructure,andwhenahighfrequencysignalistransmitted,thecharacteristicofcurrentandvoltageineachpointofthewireishigherthanthatofthetransmissionline.
Theformulaisasfollows:
'Lp2jR+PhiPhiV
=R+jwxf>>0）,verysmall,'R'（ifG'CofjG
==0Z
=
PfC2+phiI
Dependingonthetypeofsignaltransmitted,theimpedancemeasuredcanbedividedintothefollowingthree
:
Singleendedimpedance
Zse（Single,Ended）
Twodifferentialimpedance
Zdiff（Differential,Mode）
Three,samemodeimpedance
Zcom（Common,Mode）
Ingeneral,theportoftheinstrumentissingleended
Theimpedanceof50ismostcommon.IfyouwanttomeasurewithNA
Differentialsignal
"When,
Needtogothrough
Bulanconversionwill
NA
Singleendedsignal
"Convertstodifferentialsignals.
TDR
Singleendedsignal
Turn...Into
Differentialsignal
"Or"samemodesignal",justsettheinstrumentport.
Lf
GhiatekTechnologies
GoodYe,PolytronTechnologiesInc,tenthpages
Meaningofparameter
Attenuation/insertionloss
Alpha,
Attenuation/InsertionLoss）
Referstotheoutputvoltage（Vout）andtheincidentvoltage（Vin）,comparedtotheremainingsignalloss?
.
UsuallymeasuredbyNA,whichcanbedirectlymeasuredbytheinstrumentandexpressedintheformofdB
Theformulaisasfollows:
Alpha
=10log（Pout/Pin）=20log（Vout/,Vin）
IftheATTvalueiscloserto
0,thelesssignallossoccurs.Otherwise,theATTvalue
Themorenegative（smaller）is,themoreseriousthesignallossis.
Vin
Vout
GhiatekTechnologies
GoodYe,PolytronTechnologiesInc,eleventhpages
Meaningofparameter
Propagationdelaytime
Delay）
Referstothesignalinthetransmissionline,fromtheinputnumbertothereceivingend
Thetimerequiredcanbedividedaccordingtothesignaltype:
First,singleendeddelay（Single,Ended,Delay）
Two,differentialdelay（Differential,Mode,Delay）
Three,samemodedelay（CommonModeDelay）
Delay
GhiatekTechnologies
GoodYe,PolytronTechnologiesInc,Twelfthpages
Meaningofparameter
Propagationdelaytimedifference
DelaySkew）
Referstothetimedifferencebetweenthesignalandthereceiveratdifferentsignallines,thatis,Delay
Difference,thecommonDelaycanbedividedintotwokinds:
Differentialpairinternaldelay（Intra-pairSkew）referstotheinputdifferentialsignal,
DifferencebetweentheSingle-endDelayoftwowiresinthesamepairoflines（subtraction）.
Two,differencebetweenthedelaydifference（Inter-pair,Skew）,referstothedifferencebetweentheline
DifferentialDelaydifference（subtraction）.
IfthevalueoftheDelaySkewislonger,thesmallerthetimedifferenceofthesignaltransmissionis,the
Thetransmissioncharacteristicsareconsistent.
Conversely,thelargertheDelaySkewvalue,thegreaterthetimedifferenceinthesignaltransmission
Thetransmissionpropertiesofwoodareinconsistent.
GhiatekTechnologies
GoodYe,PolytronTechnologiesInc,thirteenthpages
Meaningofparameter
（difference）delaydifferencebetweentwosystems（
Inter-pairSkew）yes
Oforbetweenlines
DifferentialDelaysubtraction.
-ismorethan2timesthemeasurecalculated
InterpairSkew
GhiatekTechnologies
GoodYe,PolytronTechnologiesInc,fourteenthpages
Meaningofparameter
Differentialtointernaldelaydifference
Intra-pair,Skew）meansthesame
Oftwowiresinaline
Single-endDelaysubtraction.
-in
SettheDifferentialsignalonTDR,onetimestraight
Youcanpickitup
Skew,=0,Intra,pair,Skew
GhiatekTechnologies
GoodYe,PolytronTechnologiesInc,Fifteenthpages
Meaningofparameter
Crosstalk
Xtalk,Cross,talk）
Electromagneticnoiseoftwolinesthatinterferewitheachothergenerallyincreaseswithincreasingfrequency.
Themeasurementscanbemade
NAor
TDRtomeasure,theformulaisasfollows:
Xtalk=10,log（Pout/Pin）=20,log（Vout/,Vin）in,dB,by,NA
Xtalk=Vout/Vinin%byTDR
IftheXtalkvalueapproachesthe0dB（ornear100%）,thenoisedisturbanceismoreserious.
Conversely,theXtalkdBvalueisnegative（ornear）
0%）thereislessnoiseinterference.
GhiatekTechnologies
GoodYe,PolytronTechnologiesInc,sixteenthpages
Meaningofparameter
GhiatekTechnologies
GoodYePolytronTechnologiesInc
Crosstalkcanbedividedintotwomajorcategories:
Nearendcrosstalk
farendcrosstalk
Crosstalk（Xtalk,Cross,talk）
Vin
Vnear
NEXT=20,log（Vnear/,Vin）,in,dB,or,Vnear/,Vin,in,%
FEXT=20,log（Vfar/,Vin）,in,dB,or,Vfar/,Vinin,%
Vfar
Seventeenthpage
Meaningofparameter
Declineinrisetime
Tr,Risetime,degradation）
Whenthesignalpassesthroughtheobjecttobemeasured,thewaveformriseslonger,andthelongeritrises,thesignal
Apartialdeclineofhigherfrequency
Themoreserious,thesmallertherangeofbandwidthavailable.
0.35=risetimerecession（NS）*bandwidth（GHz）
80%
20%
DUT
Tr_sys
Tr_mea
Tr_sys:
systemrisetime（includingconnectingwiresandfixtures）
Tr_mea:
finalmeasurementtimeofrise
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