Nonlinear characterization and modeling of low frequency … · 2009-04-08 · Nonlinear...

C²S²

WorkshopWMB

Nonlinear characterization and modeling of low

frequency dispersive effects infrequency dispersive effects in power transistors

R. Quéré(1), O. Jardel(2), A. Xiong(1), M. Oualli(2), T. Reveyrand(1),

J.P. Teyssier(1), R. Sommet(1), J.C Jacquet(2) , S. Piotrowicz(2)

(1) MITIC/XLIM University of Limoges(2) MITIC/Thales 3-5 Lab

-1-

C²S² Outline

Characterization methods

Th l IThermal Issues

Trapping effectsTrapping effects

Impact Ionization effectsImpact Ionization effects

ConclusionConclusion

-2- 19/12/2008

C²S² Challenges for the design of HPA

Design of High Power Amplifiers requires accurate Non linear models that take into accurate Non linear models that take into account:

Strong Thermal constraintsStrong Thermal constraintsParasitics effects such as Traps in HEMTsImpact Ionization limits in GaAs PHEMts

To cope withTo cope withReliability issuesD d ti f L i l h t i tiDegradation of Large signal characteristics

Rely on specialized characterizations tools

-3-

y p

19/12/2008

C²S²

Characterization ToolsCharacterization Tools

-4-

C²S² Characterization of microwave devices

In the modelling process, the characterization phase is preeminent, as some effects can only be put into

id i i li d h ievidence using specialized measurements techniques.

DC and Pulsed I-V measurements

CW and pulsed S-parameters meaasurements

CW d l d L d P ll f tCW and pulsed Load-Pull frequency measurements

CW and pulsed Load-Pull time domain measurements

(LSNA)

Low Frequency Z and S parameters measurementsLow Frequency Z and S parameters measurements

Two tone IM measurements.

-5-

C²S² Pulsed Measurements of power devices

g µ

Vgs=+1.000 VVgs= +0.00nVVgs=-1.000 VVgs=-2.000 VVgs=-3.000 V

• Max current 5A

On WaferOn Wafer performances performances Vgs=-4.000 VVgs=-5.000 VVgs=-6.000 VVgs=-7.000 VVgs=-8.000 VVgs=+1.000 VVgs= +0.00nVVgs=-1.000 VVgs=-2.000 V

• Min current 1µA• Max Voltage 120V• S-parameters 1- 40 GHz

Vgs=-3.000 VVgs=-4.000 VVgs=-5.000 VVgs=-6.000 VVgs=-7.000 VVgs=-8.000 V

•Température -65°C / 200°C • Pulse duration > 300ns • duty cycle > 0.5 %

-6- 6

C²S²Principle of pulsed measurements

- short pulses 400ns : quasi –isothermal state

- period : 6µs

- starting point of the pulses is the quiescent bias point (Vgs0,Vds0) that defines the thermal and trapping state of e a a d app g s a e othe device

- small-signal RF during the steady state of the pulses

- I(V) and S-Parameters are taken during the pulsestaken during the pulses

-7-

C²S² Harmonic Load Pull ( Frequency domain analysis)

RF coupler coupler

50Ω

p p

DC biasLin Amp

D U T HN Tuner DC bias

10 MhzSynch 4 channel test set y

LO f BP

VNA receiver operation mode : Heterodyne Principle + narrow BP IF filter

LO frequency synthesis

BPFilter

Detection

Mixer

Sequential Measurements of Harmonic components Hn No phase relationship measurements between Hn and Hn+1

VNA receiver operation mode : Heterodyne Principle + narrow BP IF filter

-8-

Absolute power and power wave ratios measurements @ Hn

C²S² Load pull Time Domain Waveform Measurements

50Ω

ReferenceComb generatorFor phase cal procedure

RF coupler coupler

50Ω

Lin AmpD U T

10 Mh

Lin AmpDC bias DC biasHN Tuner

Time equivalent Waveforms @IF

10 MhzSy nch

10 20 Mhz Comb li 10 Mh 20 Mh

Harmonic Sub Sampling @ 20 MHz

10-20 MhzSynthesizer

CombGen

samplinghead

10 MhzLP filter

20 MhzADC

-9-

Frequency Translation and compression into a 10 Mhz IF Bandwidth

C²S² Pulsed LSNA-organisation

-10-

C²S² Pulsed LSNA- The stroboscopic approach

-11-

C²S² Pulsed LSNA- The set-up

-12-

C²S²

Thermal issuesThermal issues

-13-

C²S² Thermal Behaviour Impact on PA

Gain Average current

Degradation of performances for a 10W X band PA

O t t P & PAE Junction Temperature

100

120

140

era

ture

(°C

)

Outpout Power & PAE Junction Temperature

60

80

40Jun

ctio

n te

mp

e0 5 10 15 20-5 25

40

Pin (dBm)

J

Optimization of PAE allows to reach the relialbility

-14-

Optimization of PAE allows to reach the relialbility constraints for space applications

C²S² Electrothermal modeling of HBTsTRANSISTOR G A 100TRANSISTOR GaAs

DCu

DCu

AuSnTAB

PACKAGE

100 µm25 µm280 µm

25 µm

1500 µm

1( , , )B BE BCI f V V T=⎧⎪⎨

DCuBACKSIDE

+55°C

µ

125 µmAbelfilm5025E

Package

1 .2

1 .4

1 .6

[S] ( ) ( )CE C BE BP V I V I

T j Z j Pω ω

⎧ = ⋅ + ⋅⎪⎨

= ⋅⎪⎩

2 ( , , )C BE BCI f V V T⎨ =⎪⎩

0 .0

0 .2

0 .4

0 .6

0 .8

1 .0

Ic (

A )

Réseau I(V)S

(2,2

)

[S] ( ) ( )THT j Z j Pω ω= ⋅⎪⎩

Full electrothermal model2 4 6 8 1 0 1 2 1 4 1 6 1 80 2 0

-0 .2

Vc e ( V )

freq (1.000GHz to 10.00GHz)

35

40

35

40

60

80

P)m) PAE Pout Gain

Full electrothermal model requires the knowledge of

20

25

30

15

20

25

30

15

20

40

0

PA

E (%

)

Ga

in (

dB

)

Po

ut (

dB

m PAE, Pout, Gain

( )THZ ω

-15-

2 4 6 8 10 12 14 16 180 20

Pin (dBm)

C²S²

E i t l t SIMULATION

Thermal modeling of HBTs & Packaging

32

34

Experimental set up SIMULATIONThermal Model 3D finite element simulationElectrical measurement of

the thermal impedance

20

22

24

26

28

30

1

201,00E-07 1,00E-06 1,00E-05 1,00E-04 1,00E-03 1,00E-02 1,00E-01

31

32

33

34

25

26

27

28

29

30

0 50 100 150 200

HP4194A

RT

R

RRRRR

XET

uFXKXC

.

..

.

=

+−=C=20mF

R1

R2

10k

VBE0+

DC Offset=VBE0

vbe~

Model Order ReductionModel Comparison

RR

VDD1

VDD2 1/λ11

1/λ1m

1

P1

A11.P1

A1m.P1

1

A11.T11

A1m.T1m

T11

T1

-16-

1/λ1m

1

A1m.P1

T1m

C²S² Zth extraction from electrical measurements

Principle of the measurement of the input impedance

)( TIfV = ~)(~ ∂∂),( TIfV BBE =

BE TffV ~~∂∂

+∂

=∂

PZT th ).( ∂=∂ ω~~~ IVIVP +=

BITBB ITIIB

~.~00∂∂

+∂

=∂

~ )..(~~

00 CLCEf IRVhP−=

∂

00 .. CCECCE IVIVP +=

BinISOin I

TZZ ~~

.~∂∂

+= ϕ)..(~ 00 CLCEfe

B

IRVhI∂

)..().(.~00 CLCEfethinISOin IRVhZZZ −+= ωϕ

-17-

BI∂ )()( 00 CLCEfethinISOin ϕ

C²S²Extraction of φ

Vbe (V)Ib (mA) Vbe (V)Ib (mA)

Vbe (V) T (°C)Vbe (V) T ( C)φ (V/°C)

( ) BEB

VIT

ϕ ∂=

∂BoIT∂

-18-

Ib (mA)

C²S²Input impedance variation

40

50

Re{Zin}

20

30

0

10 RL< Vce0/Ic0RL= Vce0/Ic0RL > Vce0/Ic0

I {Zi }

1E1 1E2 1E3 1E41 1E5-10

Frequency (Hz)

Im{Zin}

Frequency (Hz)

)..().(.~00 CLCEfethinISOin IRVhZZZ −+= ωϕ )..().(. 00 CLCEfethinISOin IRVhZZZ + ωϕ

Zin purely real if the condition (VCE0 - RL.IC0) =0 is verified

-19-

p y ( CE0 L C0)

C²S²

3D FE Simulation Static & Dynamic

32

34

Transient regime at the selected points

26

28

30

22

24

26

201,00E-07 1,00E-06 1,00E-05 1,00E-04 1,00E-03 1,00E-02 1,00E-01

Hot points, temperature profile

Homogeneous repartition of the power

Useful tool for the design of microwave power transistorsBut huge calculation time and heavy computing ressources

-20- 19/12/2008

But huge calculation time and heavy computing ressources

C²S² Model Order Reduction

FEMRepresentation FEMRepresentation

Linear conductivity

Real system3D Modeling

y

Numerical system

3D Modeling

Thermal subcircuit

Ci it

FTKTC =+ ..

.1/λ11A11.P1 A11.T11

Reduced Order Model MOR

Circuit synthesis

1/λ1m

1

1

P1

A1m.P1

1

A1m.T1m

T11

T1m

T1

-21-

Order Model MOR1 T1m

C²S² Comparison ANSYS vs MOR (static)

The Ritz method for MOR guarantees that steady state temperature is

-22- 19/12/2008

The Ritz method for MOR guarantees that steady state temperature is reached

C²S²

Transient regime

Comparison ANSYS vs MOR (dynamic)Transient regime

Th b f Rit t d t i th i i f th t i t iThe number of Ritz vectors determine the precision of the transient regime

Computing time (30 000 nodes) ANSYS : 10 minutes (30 V) Ritz : immediate

MOR provides a significant gain of computing time without loss of precision and allows the integration of the model in CAD softwares

-23-

precision and allows the integration of the model in CAD softwares

C²S² Influence of the mounting of the transistor Zin Ritz MORZin Ritz MOR

50Re{Zth Kovar}

30

40

{ }

50 %

20

30

Re{Zth Cu}Time constants of the transistor

0

10Im{Zth Cu}

Mounting impact

-10

0

1 10 100 1000 10000 100000 1000000

Im{Zth Kovar}

-24-

1 10 100 1000 10000 100000 1000000

C²S²

10

Low Frequency S-parameters for a HBT

0

10S

11 (

dB)

-50

0

12 (

dB)

11( )dB S

-20

-10

Mag

nitu

de S

-150

-100

Mag

nitu

de S

12( )dB S

1E2 1E3 1E4 1E5 1E6 1E71E1 1E8

-30

freq Hz

M

1E2 1E3 1E4 1E5 1E6 1E71E1 1E8

-200

freq, Hz

M

MeasuresET model

Isothermal modelfreq, Hz

0

50

1

100

200

(°)

q,

12( )Sϕ

1 0

-100

-50

Pha

se S

11

-100

0

Pha

se S

12

12( )Sϕ12( )Sϕ

1E2 1E3 1E4 1E5 1E6 1E71E1 1E8

-150

-2001E2 1E3 1E4 1E5 1E6 1E71E1 1E8

-200

freq Hz

-25- 19/12/2008

freq, Hzfreq, Hz

C²S²

Trapping EffectsTrapping Effects

-26-

C²S²GaN HEMTs Characterization

S i f G N HEMTSome issues of GaN HEMTs

- Various electrical effects (traps, thermal) which cover a large frequency band from BF to RF

- Serously impact the power behavior

Useful characterization tools:

- Pulsed I-V and S-parameters

- Load Pull frequency domain measurements

- Load Pull time domain measurements (LSNA)

-27-

C²S²

Trapping Effects (1/3)Origin: Chemical defects which induce electrical defects.

Impact: Slow current transient

Ids= f (Vgs, Vds)

Ids= f(Vgs, Vds, trapping state, t )

-28-

C²S²

Trapping Effects (2/3)

Origin: Chemical defects which induce electrical defects.


Ids= f (Vgs, Vds)


f t t

-29-

fast capture

C²S²

Trapping Effects (3/3)

Origin: Chemical defects which induce electrical defects.


Ids= f (Vgs, Vds)


F t t ( )

-30-

Fast capture (~ ns)

Slow emission (up to second)

C²S²Evidence of trapping effects

g µ

Vgs=+1.000 VVgs= +0.00nV

Gate-lag: decrease of drain current

Vgs=-8V to +1V, Vgs0=-8V, Vds0=20VVgs=-8V to +1V Vgs0=-8V Vds0=25V

Drain-lag: increase of Vknee

.8 .8Vgs=-1.000 VVgs=-2.000 VVgs=-3.000 VVgs=-4.000 VVgs=-5.000 VVgs=-6.000 VVgs=-7.000 VVgs=-8.000 VVgs=+1.000 VVgs= +0.00nVVgs=-1.000 V

Vgs=-8V to +1V, Vgs0=-8V, Vds0=25VVgs=-8V to +1V, Vgs0=-8V, Vds0=30VVgs=-8V to +1V, Vgs0=-8V, Vds0=35V

.6 .6

Vgs=-2.000 VVgs=-3.000 VVgs=-4.000 VVgs=-5.000 VVgs=-6.000 VVgs=-7.000 VVgs=-8.000 V

.4 .4

.2

0

.2

0

Gate-lag Vert (Vgs0=0V,Vds0=0V)

Drain-lagVgs0=-8 V Vds0 =15 20 25 30V

0 15 20 25 30 500 15 20 25 30 50

rouge (Vgs0=-8 V, Vds0=0V) Vgs0 8 V, Vds0 15, 20, 25, 30V

Mise en évidence des pièges τcapture << t IMPULSION << τémissionD i th l t t k l i i f d

-31-

During the pulses capture takes place, emission freezed

C²S²Nonlinear electrothermal model with trapping effects

I d(T°)

Ibk

I d(T°)

Ibk

LdRd(T°)RgdCgd

Igd(T°)RgLg LdRd(T°)RgdCgd

Igd(T°)RgLg

Vgs Vds CpdCpg Vgs Vds CpdCpg

Igs(T°) Vgs_

intGate- & Drain-lagCgs

Cds

Ids (Vgs_int(t-τ), Vds(t), T°) Igs(T°) Vg

s_intGate- & Drain-lagCgs

Cds

Ids (Vgs_int(t-τ), Vds(t), T°)

Ri

Cds

Ri

Cds

Nonlinear capacitancesRs(T°)

Ls

Transistor intrinsèque Rs(T°)

Ls

Transistor intrinsèque -Nonlinear capacitances

-Current sources

-Thermal dependence

-32-

LsLs p

-Trapping sub circuits

C²S²

Steps of the modeling process

0

5

10

15

20

dB

(S

(2,1

))

50

100

150

se (

S(2

,1))

0 7

0.80.6

0.78x75 POLAR Vgs=-4.401 V, Vds=+22.97 V, Id =+0.163 A

Vgs=+1.000 VVgs= +0.00nVVgs=-1.000 VVgs=-2.000 VVgs=-3.000 VVgs= 4 000 V 5.80E-02

5.90E-02

6.00E-02

Modèle petit-signal Modèle I-V Capacités NL Modèle thermique Modèles de pièges

Étapes de modélisation

0

5

10

15

20

dB

(S

(2,1

))

50

100

150

se (

S(2

,1))

0 7

0.80.6


Vgs=+1.000 VVgs= +0.00nVVgs=-1.000 VVgs=-2.000 VVgs=-3.000 VVgs= 4 000 V

0.6


Vgs=+1.000 VVgs= +0.00nVVgs=-1.000 VVgs=-2.000 VVgs=-3.000 VVgs= 4 000 V 5.80E-02

5.90E-02

6.00E-02

5.80E-02

5.90E-02

6.00E-02

Modèle petit-signal Modèle I-V Capacités NL Modèle thermique Modèles de pièges

Étapes de modélisation

,2)

5 10 15 20 25 300 35

-60

-40

-20

0

20

40

-80

60

freq, GHz

Ph

ase

(S

(1,2

))

5 10 15 20 25 300 35

-5

0

-10

freq, GHz

d

5 10 15 20 25 300 35

-24

-22

-20

-26

-18

freq, GHz

dB

(S

(1,2

))

5 10 15 20 25 300 35

0

-50

freq, GHzP

ha

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0 0

Ids

(A)

-0.1

0

0.1

0.2

0.3

0.4

0.5

-5 0 5 10 15 20 25 30 35 40 45 50

Id e

n Am

pere

s

Vds en Volts

Vgs=-4.000 VVgs=-5.000 VVgs=-6.000 VVgs=-7.000 VVgs=-8.000 V

Idss

1,55

1,6

Is_gs

2 50E 14

3,00E-14

3,50E-14

y= 1,6E-16+1,04973E-16*EXP(T/26,3157)

Cgs_1D

4,00E-13

5,00E-13

6,00E-13MesureModele

Cgd_1D

1,00E-13

1,20E-13


Vgs intRfill

k+

+

kVds

Vgs intRfill

k+

+

kVds

5.40E-02

5.50E-02

5.60E-02

5.70E-02

5.80E 02

0.00E+00 2.00E-06 4.00E-06 6.00E-06 8.00E-06 1.00E-0

,2)

5 10 15 20 25 300 35

-60

-40

-20

0

20

40

-80

60

freq, GHz

Ph

ase

(S

(1,2

))

5 10 15 20 25 300 35

-5

0

-10

freq, GHz

d

5 10 15 20 25 300 35

-24

-22

-20

-26

-18

freq, GHz

dB

(S

(1,2

))

5 10 15 20 25 300 35

0

-50

freq, GHzP

ha

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0 0

Ids

(A)

-0.1

0

0.1

0.2

0.3

0.4

0.5

-5 0 5 10 15 20 25 30 35 40 45 50

Id e

n Am

pere

s

Vds en Volts


-0.1

0

0.1

0.2

0.3

0.4

0.5

-5 0 5 10 15 20 25 30 35 40 45 50

Id e

n Am

pere

s

Vds en Volts


Idss

1,55

1,6

Is_gs

2 50E 14

3,00E-14

3,50E-14

y= 1,6E-16+1,04973E-16*EXP(T/26,3157)

Cgs_1D

4,00E-13

5,00E-13


Cgd_1D

1,00E-13

1,20E-13


Vgs intRfill

k+

+

kVds

Vgs intRfill

k+

+

kVds

5.40E-02

5.50E-02

5.60E-02

5.70E-02

5.80E 02

0.00E+00 2.00E-06 4.00E-06 6.00E-06 8.00E-06 1.00E-0

Vgs intRfill

k+

+

kVds

Vgs intRfill

k+

+

kVds

5.40E-02

5.50E-02

5.60E-02

5.70E-02

5.80E 02

0.00E+00 2.00E-06 4.00E-06 6.00E-06 8.00E-06 1.00E-0


S(1

,1)

; S(2

10 20 300 400.0

Vds (V)

y = -0,0024x + 1,6085

1,2

1,25

1,3

1,35

1,4

1,45

1,5

0 20 40 60 80 100 120 140 160

0,00E+00

5,00E-15

1,00E-14

1,50E-14

2,00E-14

2,50E-14

0 20 40 60 80 100 120 140 160

y 1,6E 16 1,04973E 16 EXP(T/26,3157)

0,00E+00

1,00E-13

2,00E-13

3,00E-13

-10 -8 -6 -4 -2 0 2Vgs

Cgs

(F)

0,00E+00

2,00E-14

4,00E-14

6,00E-14

8,00E-14

-60 -50 -40 -30 -20 -10 0Vgd

Cgd

(F)

VdsVgs_int

VgsRfill

Rempty C

+

Vds

VdsVgs_int

VgsRfill

Rempty C

+

Vds


S(1

,1)

; S(2

10 20 300 400.0

Vds (V)

y = -0,0024x + 1,6085

1,2

1,25

1,3

1,35

1,4

1,45

1,5

0 20 40 60 80 100 120 140 160

0,00E+00

5,00E-15

1,00E-14

1,50E-14

2,00E-14

2,50E-14

0 20 40 60 80 100 120 140 160

y 1,6E 16 1,04973E 16 EXP(T/26,3157)

0,00E+00

1,00E-13

2,00E-13

3,00E-13

-10 -8 -6 -4 -2 0 2Vgs

Cgs

(F)

0,00E+00

2,00E-14

4,00E-14

6,00E-14

8,00E-14

-60 -50 -40 -30 -20 -10 0Vgd

Cgd

(F)

VdsVgs_int

VgsRfill

Rempty C

+

Vds

VdsVgs_int

VgsRfill

Rempty C

+

Vds

VdsVgs_int

VgsRfill

Rempty C

+

Vds

VdsVgs_int

VgsRfill

Rempty C

+

Vds

Dgs=f(Vgs)

Dgd=f(Vgd)Rg

RiCdsτ

Dgs=f(Vgs)

Dgd=f(Vgd)

Dgs=f(Vgs)

Dgd=f(Vgd)Rg

RiCdsτ

Dgs=f(Vgs)

Dgd=f(Vgd)

Cgs=f(Vgs)

Cgd=f(Vgd)

Ids=f(Vgs_pièges,Vds,T)

g ( g )

Rs=f(T)

Rd f(T)

gLgCpgLsCpdLd

τGmGdCgsCgdRgd

Ids=f(Vgs,Vds,T)

Dgd f(Vgd)Ids=f(Vgs,Vds)

Cgs=f(Vgs)

Cgd=f(Vgd)

Ids=f(Vgs_pièges,Vds,T)

g ( g )

Rs=f(T)

Rd f(T)

gLgCpgLsCpdLd

τGmGdCgsCgdRgd

Ids=f(Vgs,Vds,T)

Dgd f(Vgd)Ids=f(Vgs,Vds)

Rd=f(T)

Rgd=f(T)RsRd

Rgd Rd=f(T)

Rgd=f(T)RsRd

Rgd

Various parasitics effects are successively added

-33-

Various parasitics effects are successively added

C²S² Thermal effects modelled through 3D FE simulation

HEMT 1t8x75_35µm - 7W/mm_30°CGaN1.2µm/SiC440µm/AuSn45µm/Al2mm

2224

Thermal simulations (3-5 lab) Heating as a function of time

10121416182022

Zth

[°C/

W]

2468

1.E-03 1.E-02 1.E-01 1.E+00 1.E+01 1.E+02 1.E+03 1.E+04 1.E+05 1.E+06temps [µs]

ANSYS

FIT RC

Mise en équation avec des formes exponentielles

TEMP = 22,8.(1-e-t/τ1)+ 21 7 (1 e t/τ2)

R1 R2 R3 R4 R5

+ 21,7.(1-e-t/τ2) + 7.(1-e-t/τ3)

+ …Thermal subcircuit

C1 C2 C3 C4 C5

-34-

I = Pdissipée U=Tchuck_°C

T °C

C²S²Transistor parameters dependence on temperature

I-V @ various temperatures

Thermal laws

0 0049 0 68891.4

1.6

Rd0.5

0.6

0.78x75 POLAR Vgs=+0.163 V, Vds=+10.97mV, Id =-0.550mA

Vgs=+1.000 VVgs= +0.00nVVgs=-1.000 VVgs=-2.000 VVgs=-3.000 VVgs=-4.000 VVgs=-5.000 VVgs=-6.000 V

p

Equations

y = 0.0029x + 0.6375

y = 0.0049x + 0.6889

0.4

0.6

0.8

1

1.2

Rs,

Rd

Rs

0

0.1

0.2

0.3

0.4

Id e

n A

mpe

res

gVgs=-7.000 VVgs=-8.000 V

Thermal parameters- Access resistances

0 50 100 150 200T°C

-0.1-5 0 5 10 15 20 25 30 35 40 45

Vds en Volts

IV @ 25°C... Rs= Rs0+ α _Rs.TRd= Rd + α Rd T

...- Current sources- Diodes

y = -0.0008x + 1.1543

1 061.081.1

1.121.141.161.18

Idss

0 3

0.4

0.5

0.6

0.7

mpe

res

8x75 POLAR Vgs=+0.165 V, Vds=+9.709mV, Id =-0.440mA

Vgs=+1.000 VVgs= +0.00nVVgs=-1.000 VVgs=-2.000 VVgs=-3.000 VVgs=-4.000 VVgs=-5.000 VVgs=-6.000 VVgs=-7.000 VVgs=-8.000 V

Rd= Rd0+ α_Rd.TIdss= Idss0+ Idsst.TP=P0+Pt.TNgs=Ngs0+Ngst.T

1.021.041.06

0 50 100 150 200T°C

-0.1

0

0.1

0.2

0.3

-5 0 5 10 15 20 25 30 35 40 45

Id e

n A

m

Vds en Volts

Ngd=Ngd0+Ngdt.TIsgs=Isgs0+Isgst.e (T/Tsgs)

Isgd=Isgd0+Isgdt.e (T/Tsgd).

-35-

Vds en Volts

IV @ 150°C..

C²S² Topology of the trapping effects model

ff f ( )Trapping effects modify the gate command (back gating)

transients on Vgs Transients of the drain current

Ch f th it I i d tCharge of the capacitance= Ionized traps

Charge through Rcapture, Emission through Rémission

Tuning of the magnitude of theDiode= dissymetry of the capture and emission process

Tuning of the magnitude of the trapping effects

Fundamental assumption : dissymetry of the capture and emission process

-36-

Fundamental assumption : dissymetry of the capture and emission process

C²S²The model takes the knee walk out into account

1.2Measured Drain LagSimulations drain-lag ON/OFF

0.8

1.0

mm

)

0 6

0.8

1.0

1.2

mm

)

Vgs0=-7V, Vds0=25VVgs0=-7V, Vds0=0V

0.4

0.6

Ids

(A/m

0 0

0.2

0.4

0.6

Ids

(A/m

0.0

0.2

0 10 20 30 40 50Vds (V)

0.00 10 20 30 40 50Vds (V)

Pulsed Measurements

V 0 7V Vd 0 0V (bl )- Vgs0=-7V, Vds0=0V (bleu)

- Vgs0=-7V, Vds0=25V (rouge) Simulated I-V Characteristics

@ Vgs0=-7V, Vds0=0V (pointillés)

@ V 0 7V Vd 0 25V ( )@ Vgs0=-7V, Vds0=25V (rouge)

Measure @ Vgs0=-7V, Vds0=25V (bleu)

-37-

C²S²

Load pull measurements at various loads

Large signal impact of traps (1)Load pull measurements at various loads

1 : ZOPT2 Z1 2

34 1 : ZOPT

2 Z1 2

34

2 : Z2_VSWR=2.53 : Z3_VSWR=2.54 : Z4 VSWR 1 6

1 25 6

2 : Z2_VSWR=2.53 : Z3_VSWR=2.54 : Z4 VSWR 1 6

1 25 6

4 : Z4_VSWR=1.65 : Z5_VSWR=2.56 : Z6 VSWR=2.5

4 : Z4_VSWR=1.65 : Z5_VSWR=2.56 : Z6 VSWR=2.5__

Class AB, Vds=25 V , DC Bias , RF CW, 10 GHz

-38-

C²S²

L d t d f ti

Large signal impact of traps (2)

Load

Load tuned for optimum power

0.8

_int

.i

Zlo

ad

0.2

0.4

0.6

0 0

cycl

ere

seau

_IV

_sdd

..Ids

_Pièges ONPièges OFFMesure

(0.000 to 0.000)

-160

-155

a_

in)

40 250

10 20 30 40 50 600 70

0.0

indep(cycle)X1.Vd_int

-170

-165

Ph

ase

(G

am

ma

20

0

PA

E(%

)

200

150ID

S (

mA

)

0.95

in)

-5 0 5 10 15 20-10 25

-175

Pin (dBm)

-5 0 5 10 15 20-10 250

Pin (dBm)

-5 0 5 10 15 20-10 25150

Pin (dBm)316

0.85

0.90

Ma

g (

Ga

mm

a_

i

1

2

Po

ut (

W)

12

14

10

Ga

in(d

B)

-39-

-5 0 5 10 15 20-10 25

0.80

Pin (dBm)

0.0

2

0.0

4

0.0

6

0.0

8

0.1

0

0.1

2

0.1

4

0.1

6

0.1

8

0.0

0

0.2

0

0

Pin (W)

-5 0 5 10 15 20-10 2510

Pin (dBm)

C²S²Explanantion of the decrease of the average current

220

180

200

DS

(m

A)

0 -10 -5 0 5 10 15-15 20

180

160

ID

Pin (dBm)2 5

-40-


220

180

200

DS

(m

A)

0 -10 -5 0 5 10 15-15 20

180

160

ID

Pin (dBm)2 5

-41-


220

180

200

DS

(m

A)

0 -10 -5 0 5 10 15-15 20

180

160

ID

Pin (dBm)2 5

-42-


220

180

200

DS

(m

A)

0 -10 -5 0 5 10 15-15 20

180

160

ID

Pin (dBm)2 5

-43-

C²S²Validation of the model with mismatched loads

Load

TOS=1,6

0.6

0.8

s_in

t.i

Zlo

ad

0.2

0.4

0.6

0 0

cycl

ere

seau

_IV

_sdd

..IdPièges ON

Pièges OFFMesure

-160

_in

)

40 220

(0.000 to 0.000)

10 20 30 40 50 600 70

0.0

indep(cycle)X1.Vd_int

-170

-165

Ph

ase

(G

am

ma

_

20

PA

E(%

)

180

200

IDS

(m

A)

0.98

)

-10 -5 0 5 10 15-15 20

-175

Pin (dBm)

-10 -5 0 5 10 15-15 200

Pin (dBm)

-10 -5 0 5 10 15-15 20160

Pin (dBm)

2 0

2.522

0.92

0.94

0.96

Ma

g (

Ga

mm

a_

in)

1.0

2.0

Po

ut (

W)19

Ga

in(d

B)

-44-

-10 -5 0 5 10 15-15 20

0.90

Pin (dBm)

M

0.0

1

0.0

2

0.0

3

0.0

4

0.0

5

0.0

6

0.0

7

0.0

8

0.0

0

0.0

9

0.0

Pin (W)

-10 -5 0 5 10 15-15 2014

Pin (dBm)

C²S²Validation of the model with mismatched loads

Load

TOS=2,50.6

0.8

ed..Id

s_in

t.i

Zlo

ad

10 20 30 40 50 600 70

0.2

0.4

0.0

cycl

ere

seau

_IV

_sddPièges ON

Pièges OFFMesure

-155

-150

a_

in)

20

30

200

220

)

(0.000 to 0.000)indep(cycle)

X1.Vd_int

-170

-165

-160

Ph

ase

(G

am

ma

10

20

0

PA

E(%

)

180

200

160

IDS

(m

A)

0.85

n)

-5 0 5 10 15 20 25-10 30

-175

Pin (dBm)

-5 0 5 10 15 20 25-10 300

Pin (dBm)

-5 0 5 10 15 20 25-10 30160

Pin (dBm)

2.0

2.512

0.75

0.80

Ma

g (

Ga

mm

a_

i

1.0

2.0

Po

ut (

W)

8

10

6

Ga

in(d

B)

-45-

-5 0 5 10 15 20 25-10 30

0.70

Pin (dBm)

0.1 0.2 0.3 0.40.0 0.50.0

Pin (W)

-5 0 5 10 15 20 25-10 306

Pin (dBm)

C²S²

Measurements @ 5 GHz 25V dc/cw

LSNA Measurements

Measurements @ 5 GHz, 25V, dc/cw

0.4

0.5

0.1

0.2Pièges ONPièges OFFM

-0.0

0.1

0.2

0.3

Ids

-0.2

-0.1

0.0

Igs

TOS 4

5dB i

Mesure

10 20 30 40 500 60-0.1

Vds-10 -8 -6 -4 -2 0-12 2

-0.3

Vgs

0 6

0.8

0 2

0.3

5dB compression

-0.2

0.0

0.2

0.4

0.6

Ids

0 2

-0.1

0.0

0.1

0.2

Igs

TOS 3,3

320 0.8

0 10 20 30 40 50 60-10 70

0.2

-0.4

Vds-10 -8 -6 -4 -2 0-12 2

-0.2

-0.3

Vgs

7dB compression

220240260280300

Ids

(mA

)

0.2

0.4

0.6

Ids

TOS 2

-46--5 0 5 10 15 20-10 25

200220

180

Pe (dBm)

10 15 20 25 30 355 40

0.0

-0.2

Vds

TOS 2

8dB compression

C²S²Design of a 2 stages AlGaN/GaN MMIC HPA Output power PAE & Gain at 9 GHz

45

50) 35

40

P t

Output power, PAE & Gain at 9 GHz Drain Bias 32V

30

35

40

45m

) & g

ain

(dB

)

20

25

30

35

E (%

)

Pout

PAE

15

20

25

30

Pow

er (d

Bm

5

10

15

20

PAE

gain

1010 15 20 25 30 35

Input Power (dBm)

0

• Pout = 47.7 dBm ( 58 W)• PAE = 38 %

Chip size : 16.5 mm²4300x3800 µm²

1st stage : 2.4 mm• 6.5 W/mm • Gain = 14.6 dB• Vds = 32V Ids = 2 3A

State-of-the-Art Output Power with AlG N/G N MMIC HPA t X B d

g2nd stage : 8.96 mm

-47-

• Vds0 = 32V, Ids0 = 2.3A AlGaN/GaN MMIC HPA at X Band

C²S²

Impact IonizationImpact Ionization

-48-

C²S² Impact Ionization in GaAs HEMTs

0.15

0.24x75 POLAR Vgs=-1.481 V, Vds=+6.070 V, Id =+41.25µA

Vgs=+0.750 VVgs=+0.750 VVgs=+0.750 VVgs=+0.750 VVgs=+0.750 VVgs=+0.750 VVgs=+0.750 VVgs=+0.750 VVgs=+0.750 V[ ]22Yℜ

0.2A

0 05

0.1

Id e

n Am

pere

s

[ ]22

( )DS DSI V0

0.05 ( )DS DSI V

-0.050 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5 5.5

Vds en Volts 5V

Interaction between II and Traps

[ ]22YℑInteraction between II and Traps

Temperature dependence

Frequency dispersion of output[ ]

Frequency dispersion of output

conductance

-49- 19/12/2008

C²S²

I t i i ti i f d d t

PHEMT GaAs/GaInAs Model for Impact Ionization

Impact ionization is frequency dependent Model with impact ionization source

Model with impact ionization filtered around 2 GHz

-50-

Lowpass filter with a cut-off frequency of 2 GHz

C²S² Conclusions

Dispersive effects have a strong impact on transistors performances

Th l Eff i ll d iThermal Effects in all devicesTrapping effects in HEMTs (GaN and GaAs)Impact ionization effects coupled with trapping effectsImpact ionization effects coupled with trapping effects

Require specialized characterization tools Pulsed I-V and S-parameters measurementspLoad Pull Frequency and Time DomainsLow Frequency Characterization Ph i l d th l i l tiPhysical and thermal simulation

Need further investigations for checking the consistency of different kinds of characterization and modelingdifferent kinds of characterization and modeling.

To provide usefull tools for the technology assessment and improvement as well as optimization of PA performances

-51- 19/12/2008

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Nonlinear characterization and modeling of low frequency … · 2009-04-08 · Nonlinear...

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