Highly Linear Power Amplifiers for Broadband Wireless Applications

Power Amplifiers for Wireless Communications Workshop

September 9, 2002

M. Siddiqui, M. Quijije, A. Lawrence, B. Pitman, R. Katz, P. Tran, S.

Din, L. Callejo, N. Yamamoto, K. Johnson, R Lai, R. Tsai and D. Streit

2

Applications Landscape

Higher data rates dictate highly linear transmit chainsMajor contributor to linearity and cost is the driver / power amplifier combination.

Higher data rates dictate highly linear transmit chainsMajor contributor to linearity and cost is the driver / power amplifier combination.

3

• 0.15 um T-gate process

• Breakdown > 8 Volts

• fT > 85 GHz at Vds > 4 volts

• Gm > 500 mS/mm

• Imax > 500 mA/mm

• 4mil substrate thickness

• Flight qualified, commercially

proven processGaAs substrate

undoped AlGaAs

undoped AlGaAs

n+-GaAs

undoped InGaAsSi plane doping

Source DrainGate

TRW Pseudomorphic HEMT Process

4

1.E+02

1.E+03

1.E+04

1.E+05

1.E+06

1.E+07

1.E+08

1.E+09

1.E+10

1.E+11

1.5 2 2.51000/T

MT

F

• Ea 1.6 eV, Sigma = 0.6• MTF 6X1010 hours at Tj=125oC

TRW 0.15m PHEMT Process Reliability

Typical benchmark,1X106 hrs at 125C

1

10

100

1000

10000

100000

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

% Cumulative Failure

TT

F,

ho

urs

Ta=210C

Ta=265C

Ta=235C

Ta=250C

5

Summary of Circuit Performance

Part Name APH478 30 GHz

Cell

APH496 APH497 APH502 APH473 APH474

Freq

(GHz)

17-20 29-32 28-31 32-35 34-36 37-40 40-44

Gain (dB) 16 8 16 16 15 15 15

P1dB (dBm) 30.3 30.2 26.8 26.5 30.5 29.5 29.5

Density

@ P1dB

(Mw/mm)

446 436 443 414 519 400 400

P3dB (dBm) 31.5 31.5 28 28 31.5 31 31

Density

@ P3dB

(Mw/mm)

588 588 584 584 588 582 582

IDC @ 5V

(mA)

900 600 540 540 810 1080 1080

Die Size

(mm2)

5.02 1.86 2.61 2.61 3.55 4.50 4.25

State of the art output power density enables smaller die size and less DC power dissipation

State of the art output power density enables smaller die size and less DC power dissipation

6

37 to 40 GHz Power Amplifier

APH473

APH473-J Fixtured PIPO Data (250mA/mm)

111315171921232527293133

36 37 38 39 40 41

Frequency (GHz)

Gain @ 0dBm inputpower (dB)

P1dB (dBm)

P3dB (dBm)

APH473-J Fixtured IP3 Data (185mA/mm, 25 C)

36

37

38

39

40

41

42

36 37 38 39 40 41 42

Frequency (GHz)

dB

mIP3 (15dBm/tone)

IP3 (16dBm/tone)

IP3 (17dBm/tone)

IP3 (18dBm/tone)

IP3 (19dBm/tone)

IP3 (20dBm/tone)

IP3 (21dBm/tone)

IP3 (22dBm/tone)

IP3 (23dBm/tone)

Die Size = 4.5 mm2

Power Density @ P1dB = 400 mW/mm

Power Density @ P3dB = 582 mW/mm

APH473-J RF Performance

6789

1011

1213141516

36 37 38 39 40 41

Frequency (GHz)

Gai

n (

dB

)

-30-27-24-21-18-15

-12-9-6-30

gain

rlin

rlout

7

APH473-J Fixtured Gain vs Bias

8

9

10

11

12

13

14

15

16

17

34 35 36 37 38 39 40 41 42 43 44

Frequency (GHz)

250 mA/mm

200 mA/mm

150 mA/mm

100 mA/mm

50 mA/mm

APH473-J Fixtured P1dB vs Bias

202122232425262728293031

35 36 37 38 39 40 41 42

Frequency (GHz)

250 mA/mm

200 mA/mm

150 mA/mm

100 mA/mm

50 mA/mm

Performance vs. DC Bias

APH473-J Fixtured P3dB vs Bias

28.5

29

29.5

30

30.5

31

31.5

36 37 38 39 40 41

Frequency (GHz)

250 mA/mm

200 mA/mm

150 mA/mm

100 mA/mm

APH473-J Fixtured P1dB vs Bias

27

28

29

30

31

35 36 37 38 39 40 41 42

Frequency (GHz)

250 mA/mm

200 mA/mm

150 mA/mm

100 mA/mm

50 mA/mm

37 to 40 GHz Power Amplifier

8

APH473-J Fixtured IP3 Data (185mA/mm, 25 C)

36

37

38

39

40

41

42

36 37 38 39 40 41 42

Frequency (GHz)

dB

m

IP3 (15dBm/tone)

IP3 (16dBm/tone)

IP3 (17dBm/tone)

IP3 (18dBm/tone)

IP3 (19dBm/tone)

IP3 (20dBm/tone)

IP3 (21dBm/tone)

IP3 (22dBm/tone)

IP3 (23dBm/tone)

APH473-J Fixtured IP3 Data (185mA/mm, 85 C)

37.5

38

38.5

39

39.5

40

40.5

37 38 39 40 41 42

Frequency (GHz)

dB

m

IP3 (15dBm/tone)

IP3 (16dBm/tone)

IP3 (17dBm/tone)

IP3 (18dBm/tone)

IP3 (19dBm/tone)

IP3 (20dBm/tone)

IP3 (21dBm/tone)

IP3 (22dBm/tone)

Performance vs. Temperature

Gain Yield at 38.5 GHz

37 to 40 GHz Power Amplifier

9

40 to 44 GHz Power Amplifier

APH474

APH474-H Fixtured PIPO Data (250 mA/mm)

5.008.00

11.0014.0017.0020.00

23.0026.0029.0032.0035.00

39 40 41 42 43 44 45

Frequency (GHz)

dB

m

Gain @ 0dBm inputpower (dB)

P1dB (dBm)

P3dB (dBm)

APH474-H Fixtured IP3 (250mA/mm)

35.5

36

36.5

37

37.5

38

38.5

39

39.5

40

39 40 41 42 43 44 45

Frequency (GHz)

dB

m Ip3

APH474 RF Performance

02468

10

1214161820

39 40 41 42 43 44 45

Frequency (GHz)

Gai

n (

dB

)

-30-27-24-21-18-15

-12-9-6-30

gain

rlin

rlout

Die Size = 4.25 mm2

Power Density @ P1dB = 400 mW/mm

Power Density @ P3dB = 582 mW/mm

10

17 to 20 GHz Power Amplifier

APH478

APH479 Fixtured PIPO Data (250mA/mm)

10.0012.0014.0016.0018.0020.0022.0024.0026.0028.0030.0032.0034.00

16.00 17.00 18.00 19.00 20.00 21.00 22.00

Frequency (GHz)

dB

m

Gain @ 0dBmin(dB)

P1dB(dBm)

P3dB(dBm)

Die Size = 5.02 mm2

APH478 RF Performance

02468

10

1214161820

16 17 18 19 20 21 22

Frequency (GHz)

Gai

n (

dB

)

-20-17-14-11-8-5

-214710

gain

rlin

rlout

Power Density @ P1dB = 446 mW/mm

Power Density @ P3dB = 588 mW/mm

11

28 to 31 GHz Driver Amplifier

APH496

APH496-A Fixtured PIPO Data (250mA/mm, 29 C)

1012

14161820

222426

2830

26 27 28 29 30 31

Frequency (GHz)

dB

m

P1dB (dBm) @ 29 C

P3dB (dBm) @ 29 C

Gain (dB) @ 29 C

APH496-A Fixtured PIPO Data (250mA/mm, 80 C)

1012

14161820

222426

2830

26 27 28 29 30 31

Frequency (GHz)

dB

m

P1dB (dBm) @ 80 C

P3dB (dBm) @ 80 C

Gain (dB) @ 80 C

APH496 RF Performance

02468

10

1214161820

27 28 29 30 31 32 33

Frequency (GHz)

Gai

n (

dB

)

-20-17-14-11-8-5

-214710

gain

rlin

rlout

Die Size = 2.61 mm2

Power Density @ P1dB = 443 mW/mm

Power Density @ P3dB = 584 mW/mm

12

29 to 32 GHz Power Cell

Power Cell

30 GHz Cell Fixtured PIPO Data (250mA/mm)

0

5

10

15

20

25

30

35

27 28 29 30 31 32

Frequency (GHz)

dB

m

P1dB (dBm)

Gain (dB)

P3dB (dBm)

30 GHz Cell Fixtured IP3 (250mA/mm)

36

36.5

37

37.5

38

38.5

39

39.5

29 30 31 32

Frequency (GHz)

dB

m IP3

Die Size = 1.86 mm2

Power Density @ P1dB = 436 mW/mm

Power Density @ P3dB = 588 mW/mm

29 to 32 GHz Cell RF Performance

012345

6789

10

28 29 30 31 32 33

Frequency (GHz)

Gai

n (

dB

)

-20-17-14-11-8-5

-214710

gain

rlin

rlout

13

32 to 35 GHz Driver Amplifier

APH497APH497 RF Performance

02468

101214161820

30 31 32 33 34 35

Frequency (GHz)

Gai

n (

dB

)

-20-17-14-11-8-5-214710

gain

rlin

rlout

Die Size = 2.61 mm2

APH497 Fixtured PIPO Data (250mA/mm)

1012

14161820

222426

2830

31 32 33 34 35 36

Frequency (GHz)

dB

m

P1dB (dBm)

P3dB (dBm)

Gain (dB)

Power Density @ P1dB = 414 mW/mm

Power Density @ P3dB = 584 mW/mm

14

34 to 36 GHz Power Amplifier

APH502APH502 RF Performance

02468

10

1214161820

33 34 35 36 37

Frequency (GHz)

Gai

n (

dB

)

-23-20-17-14-11-8-5-214710

gain

rlin

rlout

Die Size = 3.55 mm2

Power Density @ P1dB = 519 mW/mm

Power Density @ P3dB = 588 mW/mm

APH502 CW on wafer PIPO Data (250mA/mm)

1214

16182022

242628

3032

33 34 35 36 37

Frequency (GHz)

dB

m

P1dB (dBm)

P3dB (dBm)

Gain (dB)

15

• Higher data rates dictate a need for highly linear transmit chains.

• A major contributor to linearity and cost is the driver / power amplifier combination.

• Maximizing the output power density in the driver / power amplifier chain enables

reduced die size and DC power consumption.

• Velocium’s PA MMICs have shown state of the art linearity and power density in

a production process.

Conclusion