Y. Wei, M. Urteaga, Z. Griffith, D. Scott, S. Xie, V. Paidi, N. Parthasarathy, M. Rodwell.

Department of Electrical and Computer Engineering,

University of California, Santa Barbara

yunwei@ece.ucsb.edu 1-805-893-8044 IMS2003 June 2003, Philadelphia, PA

75 GHz 80 mW InP DHBT Power Amplifier

W-band MMIC power AmplifiersIMS2003

Applications for electronics in 75-110 GHz frequency bandWideband communication systems, Atmospheric sensing, Automotive radar

2 stage 94 GHz 0.15 m InP HEMT power amplifier: Pout= 316 mW Y.C.Chen et. Al. IPRM, May 1999

Cascode 78 GHz InAlAs SHBT power amplifier: Pout= 12 mW J. Guthrie et. Al, IPRM, May 2000 Single stage 85 GHz InP DHBT power amplifiers: Pout= 40 mW Y. Wei et. Al, IMS, June 2002

This workSingle stage 75 GHz HBT power amplifiers: Pout= 80 mWTransferred substrate InP/InGaAs/InP DHBT

Highest Reported Power for HBTs in W-band

UCSBYun Wei

Transferred substrate HBT technologyIMS2003

ε=2.7

UCSBYun Wei

Gains are high at 220 GHz, but fmax can’t be extrapolated

0

10

20

30

40

1010 1011 1012

Gai

ns, d

BFrequency, Hz

U

h21

MSG

unbounded U

Vce

= 1.1 V, Ic=5 mA

0.3 m x 18 m emitter,0.7 m x 18.6 m collector

M. Urteaga

,)()(2

1cbcexcbje

ccb CRRCC

qI

kT

f

cbbbCR

ff

8max

-30

-20

-10

0

10

20

140 150 160 170 180 190 200 210 220

S21S11S22

dB

frequency (GHz)

0

10

20

30

40

1 10 100 1000

Gai

ns (

dB)

Frequency (GHz)

U

h21 462

395

343

139

InP TS DHBT: AE=0.4 x 7.5 m2, AC=1.0 x 8.75 m2, JC=1.8 mA/m2, VBR,CEO = 8 V fmax = 460 GHz, ft = 139 GHz, S. Lee DRC2002

InAlAs/InGaAs TS HBTs: 0.3 m Three-stage amplifier designs: 8.5 dB gain at 195 GHz, M. Urteaga GaAs IC 2002

Submicron transferred-substrate HBTs and amplifier IMS2003 UCSB

Yun Wei

-5

0

5

10

15

20

0

2

4

6

8

10

-15 -10 -5 0 5 10 15

Po

ut,

dB

m GT , d

B

Pin, dBm

GT Pout

IMS2003 UCSBYun Wei

8 x ( 1 m x 16 m emitter )8 x ( 2 m x 20 m collector ) Vbr_ceo>7 V, Imax=130mA

f0=85 GHz, BW3-dB=28 GHz, GT=8.5 dBP1-dB=14.5 dBm, Psat=16dBm

Transferred substrate power HBT and amplifier (IMS2002)

Q1 Q2 Q3 Q4

C

E

I0-i I0+i I0-iI0+i

Rex

Q1 Q2 Q3 Q4

C

E

Rdist I0 Rdist I0 Rdist I0 Rdist I0

Rex

common mode

f1 f2 f3 f4

I0

I0

0

differential mode

current hogging

Ic

collector

emitterbase

sub-collector

current

temperature

f1f2f3f4

4-emitter-finger HBT topology

Jc

Multiple finger thermal instability- Current HoggingLong finger thermal instability

1/stability thermal

Eballastex

JACEbe

qIkTRR

V

dT

dVK

Thermal instability in power HBTsIMS2003 UCSBYun Wei

HBT thermal stability factor

Band profileBias at Vbe=0.7 V, Vce=1.5 V

Long emitter ballasting: Lightly doped emitter expitaxy

* un=2000cm2/V.S

max_ JvqN satLDEd LDE doping level must not limit maximum current density

2_ 64 m

nqu

ttR

En

LDELDELDECONTLDE LDE resistance

emitter capInGaAs 1x1019, 300 Å

InGaAs/InAlAs 2x1019, 90 Å

InP 5x1016, 1000 Å

InP 8x1017, 300 Å

grade

LDE emitter

emitter

emitter contactTi/Pt/Au

IMS2003 UCSBYun Wei

1/4 Amp, 220 GHz fmax InP Power DHBT

UCSBYun Wei

192 m2 common base LDE DHBT

8 x ( 1 m x 24 m emitter )

8 x ( 2 m x 28 m collector )

~8 Ohm ballast per emitter finger

fmax>230 GHz

VBR_CE>7 V

Imax=250mA

0.05

0.1

0.15

0.2

0.25

-1 0 1 2 3 4 5

I C,A

Vcb

,V

0

5

10

15

20

25

109 1010 1011 1012

U, M

AG

, dB

Frequency, Hz

U

MAG

fmax

=235 GHz

Optimum load bias conditionIc=140 mA, Vce=3.7 V

IMS2003

IE step=50 mA

• Common-base, optimum load match

•8 dB gain, 21 dBm output power

•self-developed multi-finger large signal HBT model with thermal effects

•electromagnetic simulation of all passive elements (Agilent Momentum)

Amplifier DesignIMS2003

2.6 pS17

0.31 pS17

0.15 pS42

2.3 pS42

0.38 pS50

0.38 pS50 0.58 pS

37

0.58 pS37

CSiN=92fF

CSiN=92fF

CSiN=44fF

CSiN=44fF

CSiN=15fF

CSiN=15fF

-50

-40

-30

-20

-10

0

10

20

-1

0

1

2

3

4

5

80 85 90 95 100 105 110

Sij

(dB

) K,B

Frequency (GHz)

S21

S22

S11

B

K

0

5

10

15

20

25

0

2

4

6

8

10

12

14

16

-4 0 4 8 12

Po

ut (

dBm

) Gain

(dB)

Pin (dBm)

UCSBYun Wei

Amplifier Measurements

f0=75 GHz, GT=5.6 dB P1-dB=18 dBm, Psat=19 dBm @ 4dB gain

• Device dimensions: Emitter area: 1x16x16=256 m2

Collector area: 2x20x16=640 m2

• Device bias conditions: Ic=130 mA, Vce=4.5 V

Small signal measurement

Large signal measurement

IMS2003

Die size: 0.38 mm 0.89 mm

-15

-10

-5

0

5

0

5

10

15

20

25

75 80 85 90 95 100 105 110

Frequency (GHz)

K, B

Sij

(dB

)

S21

S22

S11

B

K

0

5

10

15

20

0

2

4

6

8

10

-5 0 5 10 15

Pou

t (dB

m) G

ain (dB)

PA

E (%

)

Pin (dBm)

Gain

PAE

Pout

UCSBYun Wei

Conclusions

• Demonstrated Wideband Power DHBT: Ic_max> 240 mA, Vce_BR>7 V, fmax=300 GHz

• Wideband Power amplifiers: f0=75 GHz, GT=5.6 dB, Psat=19dBm

• Multi-finger emitter ballasting scheme provides direction for future high power and high frequency MMIC work in transferred-substrate process

Future work

•Multi-stage wideband high power amplifiers

• ~200 GHz power amplifiers

Acknowledgements

This work is funded by ARO-MURI program under contract number PC249806.

UCSBYun Wei

IMS2003