Recent results on using LSVNA for Compact modeling of FETmtt11/workshops/IMS/2012/WMB/WMB-3.pdfRsw=0.991473 {o} Riw=0.275402 {o} Rgdw=0.414728 {o} Rgw=0.798131 {o} Cgdpew=20.8513 {o}

Recent results on using LSVNA for Compact modeling of GaN FET devices.

I. Angelov, M. Thorsell, K. Andersson, N. Rorsman, H.Zirath

Microwave Electronics Laboratory, Department of Microtechnology and Nanoscience MC‐2,

Chalmers University of Technology, 412 96 Gothenburg, SwedenPRESENTER ILTCHO ANGELOV [email protected]

ADDITIONAL INFO CAN BE FOUND https://document.chalmers.se/workspaces/chalmers/mikroteknologi‐och/iltcho‐angelow‐documents/openfolder

WMB: Device Model Extraction from Large-Signal Measurements

WMB: Device Model Extraction from Large-Signal Measurements IMS2012, Montreal, June 17-22, 2012 2

Model Types

• 1Physical Models- very important in the device design stage.• 2Table Based Models- accurate in the Measurement range!• Typ. 1000 measurement points! X-parameters- now!• Problems: Outside Measured Frequency Range ? Harmonics? Change of working

conditions :Temp,Rtherm,Ctherm etc. ? Manufacturing tolerances? Scaling to High Power Devices( it is easier with smaller devices and scale later). Do not provide feedback for the device quality, change of parameters-> this is important issue for foundries! Data set is large>20 mB->slow.

• 3Empirical Equivalent Circuit Models. 100-200 measurements points • Accurate enough for many applications-1-5%.• Comparably easy to understand and extract, compact form- parameter list.• Extendable out of the Measurement Range> from 65GHz to 230GHz [Ref:46-48]. • Possibility to tune& change model parameters, production tolerances, Rtherm...• Provide feedback for device parameters change, quality of processing .• All model types have their place. We should use the right type for the specific

application. We can mix& integrate different type models- example: Empirical &Physical; Empirical &Table Based ( ETB ) etc.


Important for Large&High Power devices:

• 1.The Gate Control is delayed and reduced at high frequency: • Large&High Power Devices do not respond immediately at RF! • Cdel =2-3fF- is the capacitance of the gate footprint, Rdel=2kOhm(chan.

resistance) • 2 Current slump -In some cases at RF we do not reach the DC Ids values.• 3. (Back-gate) voltage will change the effective Vgs at RF ->dispersion• 4. Higher Rs and Rd/ mm for SiC and GaN FET in comparison with GaAs FET • 5. Rd, Rs bias and temperature dependent! (A.Inoe et al., IMS2006 WE2F2, M.

Thorsel)• 6. Self-heating model-must! Mounting quality is critical. • 7. Breakdown important for high power devices!• 8 Keep device safe<Pmax!• Organize measurements properly. For GaN• Dual region measurements& simulations:• A)High Ids, Low Vds; • B)Low Ids, High Vds -Cover the load line!!!

2 4 6 8 10 12 14 16 180 20

0.1

0.2

0.3

0.4

0.0

0.5

vd

id.i

DCLowvoltage..vd

DC

Low

volta

ge..i

d.i

VdshP

max

Pmax


Ids model1: Simple 5 Parameters, Vds>Vknee: Ipks,Vpks,P1, s

-1 -0.5 0 0.5 1

Gate voltage, (V)

0102030405060

I

Idsgmpks

Vpks

Ipks

0

20

40

60

80

100

0 0,5 1 1,5 2 2,5

Ids(mA)@ Vg=0.6VIds(mA)@ Vg=0.4VIds(mA)@ Vg=0.2VIds(mA)@ Vg=0VIds(mA)@ Vg=-0.2VIds(mA)@ Vg=-0.4V

Ids(

mA

)

Vds(V)

Vknee

s

r

11 (( )); /

(1 tanh( )). tanh( )(1 )p

p m gs mpk

s

p kks m p

ds dspks ds

VP PV g I

I V VI

With 5 parameters, typical global error <10%.This simple model gives directly correct shape of the IV and Gm Single definition -∞+ ∞; Infinite & correct derivatives.

Ids, gm are exact( defined) at Vpks!

5 10 15 20 25 30 350 400.00

0.05

ts(v2)-1.5

I2dc

IdsvsVds from LSNA


Ids Model Function SelectionFET Ψ Examples GaN, SiC FET

-3

-2

-1

0

1

2

-6 -5 -4 -3 -2 -1 0 1 2

GaN

PsiSinhVd10PsiVd=10

Vgs

P1

y

-4

-3

-2

-1

0

1

-15 -10 -5 0

SiC

PsiVd10PsisinhVd10

Vgs

P1

y

a) GaAs: f1a(Vgs)=1+Tanh[P1.Vgs]Ψ1a(Vgs)=ArcTanh[(Ids/Ipk0)-1]

b) GaN and SiC: f1b(Vgs)=1+Tanh[Sinh(P1.Vgs)]Ψ1b(Vgs)=ArcSinh[ArcTanh[(Ids/Ipk0)-1]]

c)Directly extractable; d)Using Tanh[Sinh] improves the harmonics fit for low P1<1


Ids Model Function Selection forComplicated Gm

-3 -2 -1 0 10.0

0.2

0.4

0.6

0.8

1.0

1.2

1.4

Gate voltage, V

gm,A

v

-2.5 -2.0 -1.5 -1.0 -0.5 0.0 0.5-3.0 1.0

0.02

0.04

0.06

0.08

0.10

0.00

0.12

Vgs

mag

(Y(2

,1))

At some moment we should stop to increase parameters-> we can switch to Table Based Model, Xparameters , ETB !!!

Vpks2=-2.0v; Vpks=-0.3V, AA=0.1;Ids=Ipk0T*(1+AA*tanp+(1-AA)*tanp11)*tanh(alphap*Vds)*(1+lambdap*Vds+Lsb0*exp(Ebd*(Vds-Vtr)))Vpkm=Vpks -DVpks+DVpks*tanh(Alphas*Vds)-Vbg-Vsb2*(Vdg-Vtr)^2Vpkm2=Vpks2 -DVpks+DVpks*tanh(Alphas*Vds)-Vbg-Vsb2*(Vdg-Vtr)^2


GaN GS,GD, DC Breakdown MeasurementsCompliance is not fast enough and difficult to model

GateGroundedGSJunctionBrekdown

Vsi

Drain

SourceFET05mmX1

RR5R=1 kOhm

RR4R=1 MOhm

I_Probeidsp

DCDC1

Step=0.1Stop=2Start=-20SweepVar="vg"

DCV_DCSRC2Vdc=vg

I_Probeigp

-18 -16 -14 -12 -10 -8 -6 -4 -2 0-20 2

-1.5

-1.0

-0.5

0.0

0.5

1.0

-2.0

1.5

vg

igp.

i, m

A

m1

m1vg=igp.i=0.001

2.000

Vdsi

Vsi

CommongateDG JunctionBreakdown

ÿDrain

GateSource

FET05mmDevDVerilogMX1

I_ProbeidspI_Probe

igp

V_DCSRC2Vdc=vd

RR4R=50 Ohm

DCDC1

Step=0.1Stop=40Start=-1SweepVar="vd"

DC

VARVAR1

vd = 0 Vvg = 1 V

EqnVar

RR5R=1 MOhm

m1indep(m1)=plot_vs((idsp.i), vd)=-0.003

40.000

4 9 14 19 24 29 34-1 39

-0.003

-0.002

-0.001

0.000

0.001

-0.004

0.002

vd(id

sp.i)

m1m1indep(m1)=plot_vs((idsp.i), vd)=-0.003

40.000

Rmeas=1 kOhm defines the current in the measuremnt pathRcon=1MOhm defines the current in the connected path.Injected current <0.1mA/mm for safety!!!Setup can be combined with LSNA measurements.

Gate -Source breakdown measurement setup.

Gate -Drain breakdown measurement setup


Resitances Rd,Rs for GaN depend strongly on the dissipated power!

1

2

3

4

5

6

7

8

0

0.5

1

1.5

2

2.5

3

3.5

-1.5 -1 -0.5 0 0.5 1

Pdc=const

RdVd8

RdVd14

RdVd10

PdcVd8

PdcVd10

PdcVd14

Rd(

Ohm

)

Pdc(W)

Vgs(V)

RdCappy; Berroth- Cold FET method (VDS=0) for extraction will not give correct results for GaN!The reason : Rs and Rd are bias and temperature dependent. GaN Resitances Rd,Rs depend strongly on the dissipated power. For constant power they are quite constant with Vds. When cold values for Rs and Rd are used, unrealisticly high Output Power and PAE will be predicted! Cold values should be used only as a start and limit the optimization values.

Bias dependence Rd,Pdc vs. Vgs(Ids)


GaN Dispersion Modelling Implementation

1 Simple> Rc,Crf at the ouput,input , usually implemented in CAD toolsThough :Rc is bias dependent! Rc1=Rcmin+Rc/(1+tanp)

2 Back-gate Approach: (J. Conger, A. Peczalski, M. Shur, SC,Vol. 29, No.1)3 Physical Approach: (K. Kunihiro, Y.Ohno, ED, Vol. 43, No. 9)4 Device is symmetric>output and input dispersion: Rcin,Crfin

ADS2009 GaN Extended dispersion Modelling–combined Rc and back-gate+ Rdel,Cdel:8 par.


GaN model implemented in VerilogA summary :

1 f1(Ψ(Vgs))=1+Tanh[Sinh(P1.Vgs)]

2 Cap model with peaking Cgs

3 Rd and Rs are bias( Rd2) and temperature dependent (TcRs),Rsbdep=Rs*(1+Rd2*(1+tanh(Ψ))); Rdbdep=Rd*(1+Rd2*(1+tanh(Ψ))); Bias dependence Rd2 for Rs, Rd is the same dependence as Ids.RsbdepT=Rsbdep*(1+TcRs*DTj); RdbdepT=Rdbdep*(1+TcRs*DTj);

4 Dispersion(Rc,Rcmin,Crf,Rcin Crfin)+2 new options :1Backgate Kbgate 2 Rdel, Cdel

5 Breakdown for GS,GD Junctions: Kbdgate,Vbdgs,Vbdgd, Pbdg

6 GaN+Noise :RF and LF;

7VA implementation :Many functional changes made by Tiburon to improve the stability.


VA Model Parameters GaN tot. 69GaN Ids parameters:12Cap parameters:15Thermal parameters:8Igs:3

30

Parasitics&packageFETGaN2FET1

tau=2 psecPbdg=0.45Vbdgd=50 VVbdgs=10 VKbdgate=0.0001Vsb2=0 VEbd=0.3Vbdrain=60 VLsb0=0.05Cdel=2 fF

Rdel=2 kOhmRcin=500 kOhmCrfin=20 fFKbgate=0.01Crf=100 fFRc=10 kOhmRcmin=0.4 kOhmLs=8.8 pHLd=100 pHLg=100 pHRdsleak=1 GOhmRgsleak=1 GOhmRgdleak=1 GOhmRgd=5 OhmRd2=0 Ohm

Rd=1.55 OhmRs=0.88 OhmRi=2.5 OhmRg=2.5 OhmVjg=0.9 VPg=15.2Ij=0.0005 ATamb=25TcRtherm=0.005TcCrf=+0.002TcCgd0=+0.002TcCgs0=+0.002TcRs=+0.0002TcP1=-0.0025TcIpk0=-0.004

Ctherm=0.001 FRtherm=8.5 OhmP111=0.008P41=0.25P40=0.48P31=0.21P30=0.03P21=0.21P20=0.03P11=0.25P10=0.48Cgdpe=8 fFCgd0=376 fFCgdpi=200 fFCgs0=3500 fF

Cgspi=615 fFCds=800 fFB2=3.0B1=0.08Lvg=0.000lambda=0.02Alphas=0.7Alphar=0.1P3=0.05P2=-0.03P1=0.62DVpks=0.5 VVpks=-2.4 VIpk0=0.61 AIdsmod=1

Breakdown:7Dispersion:8

VARVAR23

Wtot=Nfing*Wfing/1000Wfing=100Nfing=4

EqnVarVAR

VAR21

Ijw=0.00006Rthermw=6Rcminw=0.622729 oTauw=0.772053 oLsw=9.3351 oLdw=36.5984 oLgw=3.01362 o

EqnVar

VAR5

Tau=Tauw*WtotRcmin=Rcminw/WtotIj=Ijw*WtotLs=5 +Lsw*Wtot

Ld=10 +Ldw*Wtot/NfingLg=10 + Lgw*Wtot/NfingRth=0.1+Rthermw/WtotRgd=0.1+Rgdw/WtotRd=0.1+Rdw/WtotRs=0.1+Rsw/WtotRi=0.1+Riw/WtotRg=0.1+Rgw/WtotCgdpe=3+Cgdpew*(Wtot)Cgd0=3+Cgs0w*(Wtot)Cgdpi=3+Cgdpiw*(Wtot)Cgs0=5+Cgs0w*(Wtot )Cgspi=5+Cgspiw*(Wtot)Cds=5+Cdsw*(Wtot)Ipk0=Ipk0w*WtotVAR24

Rdw=4.92371 oRsw=0.991473 oRiw=0.275402 oRgdw=0.414728 oRgw=0.798131 oCgdpew=20.8513 oCgdpiw=72.5009 oCgs0w=397.479 oCgspiw=41.9464 oCdsw=280.572 oP3=0.399587 -oP1=0.769999 oIpk0w=0.55 o

Ipk0 and Cgs0 scale were well!Using layout, parasitics scale very well

InputPadPortGateNum=1

MLINTL17

L=119 umW=50 umSubst="MSub1"

PortDrainNum=2

MTAPERTaper6

L=70 umW2=96 umW1=50 umSubst="MSub1"

MLINTL18


MTAPERTaper7


MLINTL8


MTAPERTaper4


MLINTL16


MTAPERTaper5


PortP3Num=3

Angelov_FETANGELOV2

Trise=Temp=Model=ANGELOVM1

MLINTL19


MLINTL10


RR4R=0.05 Ohm

RR3R=0.05 Ohm

VI AV5

T= 3 umH= 1 0 0 umD2 = 1 1 0 umD1 = 7 0 um

VI AV4

T= 3 umH= 1 0 0 umD2 = 1 1 0 umD1 = 7 0 um


Ron=Rd+Rs+Rch is the first we need to find.

1

10

100

1000

104

105

106

107

-2 -1,5 -1 -0,5 0 0,5

Vds=1Rds2=10kOhm

Ron=6 Ohm

RdsRds2

Rds

Vgs

Roff=5MOhm

Roff=10kOhm

1 2 3 4 5 6 7 8 9 10 11 12 13 140 15

0.1

0.2

0.0

0.3

VDS

Idsm

0

5

10

15

20

25

30

-0.6 -0.4 -0.2 0 0.2 0.4 0.6 0.8

ids(vg)

Ids(mA)@Vd=0.2V

Ids(

mA

)

Vgs(V)

Nonlinear Models for currents& capacitances are controlled by intrinsic voltages. We need Rs,Rd to account for the voltage drop on Rs, Rd.Ids vs. Vgs for low Vds, below the knee region in the linear part of the IV: sweeping Vgs, fixed low Vds. ->safe measurement, GaN-> Vds=1v, GaAs-> Vds=0.1v . Rds(Ron)=Vds/Ids: For gate in the middle S-D :Rs=Rd=Rch=Rds/3 Very good staring values for optimization.

GaN,Vds=1V Ids vs. Vgs,Vd=1Good device:Ron=3 oHm,Roff>3MOhmWorking device:Ron=6 oHm;Roff=10 kOhm

Do not forget to measure resistances in the bias lines!!!


LSVNA Measurement Set-up Active Load Pull

It is very fast& accurate!The amplifier at the output should provide enough power to compensate circulator&cable losses ( 2-3 dB).

The circulator separates the injected and outgoing wave, terminating b2 in a 50 Ω load. This gives full control of ΓL seen by the DUT at f0, according to:

2 2 21 2 2 2

2

; ; ;2 2

where Zc is the system impedance.

IN OUTC C

a b a aP PZ Z b

02

,

02

020

0,fb

eVVAfbfa

fQI VVj

QI


Ids=f(Vgs) model extractionTwo frequencies Low RF an High RF

m11indep(m11)=plot_vs(ts(i2.i), ts(v1))=0.277INDEX=1.000000

-1.063

-3.5 -3.0 -2.5 -2.0 -1.5-4.0 -1.0

0.075

0.150

0.225

0.000

0.300

ts(v1)

ts(i2

.i)

m11m11indep(m11)=plot_vs(ts(i2.i), ts(v1))=0.277INDEX=1.000000

-1.063

Active load RF=0.1GHzIsatindep(Isat)=plot_vs(ts(i2m), ts(v1m))=0.215INDEX=1.000000

-1.728

-5.5 -5.0 -4.5 -4.0 -3.5 -3.0 -2.5 -2.0-6.0 -1.5

0.00

0.05

0.10

0.15

0.20

-0.05

0.25

ts(v1)

ts(i2

.i)

ts(v1m)

ts(i2

m)

IsatIsatindep(Isat)=plot_vs(ts(i2m), ts(v1m))=0.215INDEX=1.000000

-1.728

Active load Pin=12dBm,RF=3Ghz

LF RF ->current models, High RF-> Cap models

We need: Ipks,Vpks,P1=Gm/Ipks, s1.Read the maximum current. Ipks=Imax/22.Read the gate voltage Vpks for Imax/23.Adjust P1 to get the slope ( gm) correctYou have the gate part of the model ready.

1. Derivatives, inflection voltage forthe current and capacvitances are the same!Start with P1=P11=P41;P10=P40P21=P31= Alphar

Vpks


1LS Harmonics Evaluation- Power Spectrum

For LS & Harmonics modelling we need correct derivativesSelf-Heating, Dispersion, Memory effects, complicate the picture. DC data for Ids harmonics are often noisy! Solutions:1Power Spectrum Evaluation (PS)using LSVNA, Spectrum Analizer ,Power meter; 2Load Pull or LSNA or Combined Load Pull & LSNA Evaluation!!

-1.3 -1.1 -0.9 -0.7 -0.5 -0.3 -0.1 0.1 0.3-1.5 0.5

-20

0

20

-40

Vgs

dBm

(Vlo

ad[::

,1])

m1

VGSdB

m(P

out1

mea

s)

m2

dBm

(Pou

t2m

eas)

dBm

(Pou

t3m

eas)

dBm

(Vlo

ad[::

,2])

dBm

(Vlo

ad[::

,3])

-1.5 -1.0 -0.5 0.0-2.0 0.5

-20

-10

0

10

20

-30

30

Vgs

dBm

(v2[

::,2]

)dB

m(v

2[::,

3])

dBm

(v2[

::,1]

)

m1

VGS

dBm

(Pou

t2m

eas)

dBm

(Pou

t3m

eas)

dBm

(Pou

t1m

eas)

m2

PS: GaN C-band and X- band Measured and modeled


PS optimization. Minimize error for Ids, 1-st, 2-nd,3-rd harmonics .

v1

v2

DataAccessComponentDAC3

iVal2=1iVar2="FREQ"iVal1=INDEX-1iVar1="INDEX"ExtrapMode=Interpolation ModeFile="MGANND5VD15powerspectrum.c iti"

DAC


iVal2=freq/fundamentaliVar2="FREQ"iVal1=INDEX-1iVar1="INDEX"ExtrapMode=Interpolation ModeFile="MGANND5VD15powerspectrum.citi"

DAC


iVal2=1iVar2="FREQ"iVal1=INDEX-1iVar1="INDEX"ExtrapMode=Interpolation ModeFile="MGANND5VD15powerspectrum.c iti"

DAC


iVal2=0iVar2="FREQ"iVal1=INDEX-1iVar1="INDEX"ExtrapMode=Interpolation ModeFile="MGANND5VD15powerspectrum.citi"

DAC

FET05mmG2X1

OptimOptim1

EnableCockpit=yesSaveCurrentEF=noUseAllGoals=yes

UseAllOptVars=yesSaveAllIterations=noSaveNominal=yesUpdateDataset=yesSaveOptimVars=yesSaveGoals=yesSaveSolns=yesSetBestValues=yesNormalizeGoals=noFinalAnalysis="None"StatusLevel=4DesiredError=0.0MaxIters=1ErrorForm=L2OptimType=Random

OPTIM

GoalOptimGoal6

RangeMax[1]=RangeMin[1]=RangeVar[1]=Weight=1Max=1e-2Min=-1e-2SimInstanceName="HBsimulationExpr="ErrorIds"

GOAL

MeasEqnMeas4

ErrorIds=(Idsmeas-Idssim)ErrorP3=P3meas-P3simErrorP2=P2meas-P2simErrorP1=P1meas-P1sim

EqnM eas VAR

VAR4

numberOfHarmonics=4fundamental=4 GHzINDEX=2INDEXmax=10

EqnVar

MeasEqnMeas7

ErrorP3L=real((P3measL-P3simL)/P3measL)ErrorP2L=real((P2measL-P2simL)/P2measL)ErrorP1L=real((P1measL-P1simL)/P1measL)

EqnM eas

MeasEqnMeas6

P3simL=v2[::,3]P2simL=v2[::,2]P1simL=v2[::,1]

EqnM eas

GoalOptimGoal5

RangeMax[1]=RangeMin[1]=RangeVar[1]=Weight=1Max=1e-2Min=-1e-2SimInstanceName="HBsimulation"Expr="ErrorP3L"

GOAL

GoalOptimGoal4


GOAL

GoalOptimGoal3


GOAL

MeasEqnMeas5

P3measL=v2m[::,3]P2measL=v2m[::,2]P1measL=v2m[::,1]

EqnM eas

VARVAR5

V2DC=fileDAC2,"V2"V1DC=fileDAC2,"V1"

EqnVar

MeasEqnMeas8

Igssim=real(i1.i[::,0])Idss im=real(i2.i[::,0])

EqnM eas

MeasEqnMeas2

P3sim=dbm(v2[::,3])P2sim=dbm(v2[::,2])P1sim=dbm(v2[::,1])

EqnM easMeasEqn

Meas1

Igsmeas=real(i1m[::,0])Idsmeas=real(i2m[::,0])P3meas=dbm(v2m[::,3])P2meas=dbm(v2m[::,2])P1meas=dbm(v2m[::,1])

EqnM eas

LL2

R=1L=1.0 mH

LL1

R=1L=1.0 mH

V_DCSRC3Vdc=real(V1DC)

I_ProbeIgsDC

HarmonicBalanceHBsimulation

Order[1]=numberOfHarmonicsFreq[1]=fundamental

HARMONIC BALANCE

I_ProbeIdsDC V_DC

SRC4Vdc=real(V2DC)

VARVAR1

b1m=(v1m-50*i1m)/2a1m=(v1m+50*i1m)/2b2m=(v2m-50*i2m)/2a2m=(v2m+50*i2m)/2P1m=fileDAC3, "V2"i2m=fileDAC1, "I2"i1m=fileDAC1, "I1"v2m=fileDAC1,"V2"v1m=fileDAC1,"V1"

EqnVar

VARVAR8V1in=real(v1m[::,1])

EqnVar

V_1ToneSRC1

Freq=fundamentalV=0 V_All=2*a1m

V_1ToneSRC2


RR2R=50R

R3R=50

DC_BlockDC_Block1

I_Probei1

DC_BlockDC_Block2

I_Probei2

Power Spectrum IV optimization using LSVNA data.Operating voltages, Pin for model simulations are calculated from the measured waveforms.


2Optimization using LSNA Active Load Pull Data

v1

v2

OptimOptim1

UseAllOptVars=yesSaveAllIterations=noSaveNominal=yesUpdateDataset=yesSaveOptimVars=yesSaveGoals=yesSaveSolns=yesSetBestValues=yesNormalizeGoals=noFinalAnalysis="None"StatusLevel=4DesiredError=0.0MaxIters=5ErrorForm=L2OptimType=Random

OPTIM

GoalOptimGoal7

RangeMax[1]=RangeMin[1]=RangeVar[1]=Weight=1Max=1e-2Min=-1e-2SimInstanceName="HBsimulation"Expr="ErrorGamma"

GOAL

MeasEqnVoltageWavefroms

b2sim=(v2-i2.i*50)/2a2sim=(v2+i2.i*50)/2b1sim=(v1-i1.i*50)/2a1sim=(v1+i1.i*50)/2

EqnM eas

MeasEqnMeas7

ErrorP3L=real((P3measL-P3simL)/P3measL)ErrorP2L=real((P2measL-P2simL)/P2measL)ErrorP1L=real((P1measL-P1simL)/P1measL)

EqnM eas

MeasEqnMeas6

P3simL=v2[::,3]P2simL=v2[::,2]P1simL=v2[::,1]

EqnM eas

MeasEqnLoadReflection

ErrorGamma=abs(real(GammaSim)-real(GammaM))+abs(imag(GammaSim)-imag(GammaM))GammaM=a2m[::,1]/b2m[::,1]GammaSim=a2sim[::,1]/b2sim[::,1]

EqnM eas

MeasEqnMeas5

P3measL=v2m[::,3]P2measL=v2m[::,2]P1measL=v2m[::,1]

EqnM eas

MeasEqnMeas4

ErrorIds=real((Idsmeas-Idssim)/Idsmeas)ErrorP3=P3meas-P3simErrorP2=P2meas-P2simErrorP1=P1meas-P1sim

EqnM eas


iVal2=0iVar2="FREQ"iVal1=INDEX-1iVar1="INDEX"ExtrapMode=Interpolation ModeFile="MGAND15VGm04LP02.citi"

DAC

VARVAR1

b1m=(v1m-50* i1m)/2a1m=(v1m+50* i1m)/2b2m=(v2m-50* i2m)/2a2m=(v2m+50* i2m)/2i2m=fileDAC1, "I2"i1m=fileDAC1, "I1"v2m=fileDAC1,"V2"v1m=fileDAC1,"V1"

EqnVar



DAC

MeasEqnMeas2

P3sim=dbm(v2[::,3])P2sim=dbm(v2[::,2])P1sim=dbm(v2[::,1])

EqnM eas

MeasEqnMeas1

Igsmeas=real(i1m[::,0])Idsmeas=real(i2m[::,0])P3meas=dbm(v2m[::,3])P2meas=dbm(v2m[::,2])P1meas=dbm(v2m[::,1])

EqnM eas

VARVAR4

numberOfHarmonics=4fundamental=4 GHzINDEX=1INDEXmax=7

EqnVar



DAC



DAC


iVal2=freq/fundamentaliVar2="FREQ"iVal1=INDEX-1iVar1="INDEX"ExtrapMode=Interpolation ModeFile="MGAND15VGm04LP02.citi"

DACHarmonicBalanceHBsimulation

Order[1]=numberOfHarmonicsFreq[1]=fundamental

HARMONIC BALANCE

MeasEqnMeas3

Igssim=real(IgsDC.i[::,0])Idssim=real(IdsDC.i[::,0])

EqnM eas

VARVAR5

V2DC=fileDAC2,"V2"V1DC=fileDAC2,"V1"

EqnVar

FET05mmG2X1

I_ProbeIgsDC

I_ProbeIdsDC

TLINTL1

F=4 GHzE=-1Z=50.0 Ohm

RR3R=50

V_1ToneSRC1


V_1ToneSRC2


RR2R=50

DC_BlockDC_Block2

I_Probei2

I_Probei1DC_Block

DC_Block1

DC_FeedDC_Feed2

V_DCSRC4Vdc=real(V2DC)DC_Feed

DC_Feed1V_DCSRC3Vdc=real(V1DC)

Optimization Loadpul :one goal- gamma error. Operating voltages, Pin for model simulations are calculated from measured waveforms.


Combined LSNA & Load-Pull Measurements -the best approach for LS evaluation for GaN

INDEX (1.000 to 32.000)

a2_s

im[::

,1]/b

2_si

m[::

,1]

a2[::

,1]/b

2[::,

1]

-1.4 -1.2 -1.0 -0.8 -0.6 -0.4 -0.2 0.0 0.2 0.4-1.6 0.6

2.0

2.5

3.0

3.5

1.5

4.0

VGS

Pou

t1m

eas

V

mag

(Pou

t1si

m)

-1.4 -1.2 -1.0 -0.8 -0.6 -0.4 -0.2 0.0 0.2 0.4-1.6 0.6

0.5

1.0

1.5

2.0

0.0

2.5

VgsP

dcsi

mP

dcm

eas

100 200 300 4000 500

-0.10-0.050.000.050.100.15

-0.15

0.20

Time(ps)

Ids(

A)

5 10 15 20 25 300 35

-0.050.050.15

-0.15

0.25

Vds(V)

Igat

e (A

)

100 200 300 4000 500

-0.10-0.050.000.050.10

-0.15

0.15

Time(ps)

Igat

e(A

)

5 10 15 20 25 300 35

-0.050.050.15

-0.15

0.25

Vds(V)

Ids(

A)

-4 -3 -2 -1 0-5 1

-0.050.050.15

-0.15

0.25

Vgs(V)

Igat

e(A

)

-4 -3 -2 -1 0-5 1

-0.050.050.15

-0.15

0.25

Vgs(V)

Ids(

A)

a)

b)

c)

d)

e)

f)

Measured (points) and modeled RF and DC Power Load Pull C- band

Measured and simulated Load Impedances C band.I2,V2 should be correct to get this right!

Measured and modeled Waveforms Vds=15V; C -band Harmonic Load pull evaluation.


3LSNA & Load-Pull Measurements:GaN Knee walkout evaluation:Real Active Load Evaluation

INDEX (1.000 to 8.000)

Z

2 3 4 5 6 71 8

29

30

31

32

33

28

34

INDEX

dBm

(v2m

[::,1

])

5 10 15 20 25 300 35

0.07

0.14

0.21

0.28

0.00

0.35

Vds(V)

Ids(

A)

Zl from 50 to 280 oHm

Sweeping real Zload RF=4 GHz;Pin=14 dBm GaN DC Ids (red) and dynamic Ids(Blue) sweeping real ZloadThe high freqency IV slump is accuratelly modeled with the Rd2 and gate control network Rdel,Cdel

2GHz

2 4 6 8 10 12 140 16

0.00

0.05

0.10

0.15

0.20

-0.05

0.25

v2mts

i2m

ts

v2sts

i2st

si1

mts

i1st

s

5 6 7 8 9 104 11

-0.05

0.00

0.05

0.10

0.15

-0.10

0.20

v2sts

i2m

tsi2

sts

i1m

tsi1

sts

12GHZ 18GHz

6.5 7.0 7.5 8.0 8.5 9.06.0 9.5

0.00

0.05

0.10

-0.05

0.15

v2sts

i2m

tsi2

sts

i1m

tsi1

sts

Knee walkout: 2GHz Vmin=0.8V(DCKnee GaAs) 12GHz Vmin=4.5V 18GHz Vmin=6.3V

Knee walkout is modeled with Rd2


Typical results after the optimizations.Accuracy in the range better 5%

2 3 4 5 6 7 81 9

15.5

23.0

30.5

8.0

38.0

INDEX

dBm

(v2[

::,1

])

m5

dBm

(v2m

[::,

1])

m6

m5INDEX=dBm(v2[::,1])=33.466

9.000m6INDEX=dBm(v2m[::,1])=33.403

9.000

INDEX (1.000 to 9.000)

a2[:

:,1]

/b2[

::,1

]a2

m[:

:,1]

/b2m

[::,

1]

2 3 4 5 6 7 81 9

0.0250.0500.0750.1000.1250.1500.1750.2000.2250.2500.2750.3000.3250.3500.3750.4000.4250.4500.475

0.000

0.500

INDEX

PAEm

eas

m7

PAEs

im

m8

m7INDEX=PAEmeas=0.458

9.000m8INDEX=PAEsim=0.451

9.000

2 3 4 5 6 7 81 9

3.4

3.6

3.8

4.0

4.2

4.4

4.6

3.2

4.8

INDEX

mag

(Prfm

eas)

m9

mag

(Prfs

im)

m10

m9INDEX=mag(Prfmeas)=3.861

6.000

m10INDEX=mag(Prfsim)=3.970

6.000

Eqn DPAEmeas=100*(PAEmeas-PAEsim)/PAEmeas

2 3 4 5 6 7 81 9

0.5

1.0

1.5

2.0

2.5

3.0

0.0

3.5

INDEX

DPm

DPA

Emea

s

Load Pull 7 Ghz Vd20v Pin 18 dBm

Load Pull 7 Ghz Vd20v Pin 18 dBm


Self-heating measurement and modeling problems LSNA users should be aware!LSNA measurement at single temperature is not enough to evaluate self-heating properties.

3 6 9 12 15 18 21 24 270 30

0.09

0.18

0.27

0.36

0.00

0.45

vd

DC

2.D

C.id

sp.i,

A

Vdsexp

Idse

xp

3 6 9 12 15 18 21 24 270 30

0.09

0.18

0.27

0.36

0.00

0.45

vd

DC

2.D

C.id

sp.i,

A

Vdsexp

Idse

xp

INDEX (1.000 to 9.000)

a2[::

,1]/b

2[::,

1]a2

m[::

,1]/b

2m[::

,1]

m1INDEX=dBm(v 2[::,1])=33.696

9.000

2 3 4 5 6 7 81 9

15.5

23.0

30.5

8.0

38.0

INDEX

dBm

(v2[

::,1]

)

m1

dBm

(v2m

[::,1

]) m1INDEX=dBm(v 2[::,1])=33.696

9.000

m10INDEX=mag(Prf sim)=3.970

6.000

2 3 4 5 6 7 81 9

3.4

3.6

3.8

4.0

4.2

4.4

4.6

3.2

4.8

INDEX

mag

(Prfm

eas)

mag

(Prfs

im)

m10



9.000

2 3 4 5 6 7 81 9

0.0250.0500.0750.1000.1250.1500.1750.2000.2250.2500.2750.3000.3250.3500.3750.4000.4250.4500.475

0.000

0.500

INDEX

PAEm

eas

PAEs

im

m8

m8INDEX=PAEsim=0.451

9.000

INDEX (1.000 to 9.000)

a2[::

,1]/b

2[::,

1]a2

m[::

,1]/b

2m[::

,1]

m1INDEX=dBm(v 2[::,1])=33.681

9.000

2 3 4 5 6 7 81 9

15.5

23.0

30.5

8.0

38.0

INDEX

dBm

(v2[

::,1]

)

m1

dBm

(v2m

[::,1

]) m1INDEX=dBm(v 2[::,1])=33.681

9.000


6.000

2 3 4 5 6 7 81 9

3.4

3.6

3.8

4.0

4.2

4.4

4.6

3.2

4.8

INDEX

mag

(Prfm

eas)

mag

(Prfs

im)

m10



9.000

2 3 4 5 6 7 81 9

0.0250.0500.0750.1000.1250.1500.1750.2000.2250.2500.2750.3000.3250.3500.3750.4000.4250.4500.475

0.000

0.500

INDEX

PAEm

eas

PAEs

im

m8

m8INDEX=PAEsim=0.451

9.000

Rtherm=26 Ohm ,PAE=0.451Output power 33,681 dBm

Rtherm=6 oHm,PAE=0.451 Output power 33,696 dBm

Rtherm 6 ohm Rtherm 26 ohmLSVNA results are not sensitive to Rthermalchanges .Additional measurements needed to extract Rthermal!


Conclusions:

LSVNA is very important and useful tool for evaluating the quality of new devices!Arranging measurements in two frequency ranges:Low RF and high RF, simplifies evaluation procedure and model extraction. At low RF Ids parameters are evaluated and extracted and at High RF- reactive part .A general purpose large-signal modeling approach for GaN FET was proposed, implemented in CAD tools and evaluated experimentally with DC, S-par, LSVNA with devices from different foundries. Models show good accuracy and stable behavior in HB simulations. Thank you for your attention! S.D.GL.

Questions?Meyer’s Law, part of Murphy’s Law:It is a simple task to make things complex, but a

complex task to make them simple.


References

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Documents

Recent results on using LSVNA for Compact modeling of FETmtt11/workshops/IMS/2012/WMB/WMB-3.pdfRsw=0.991473 {o} Riw=0.275402 {o} Rgdw=0.414728 {o} Rgw=0.798131 {o} Cgdpew=20.8513 {o}