gabriele fmicone, phd - ieee › phoenix-wad › files › 2016 › 10 › ...sep 15, 2016 · 15...

1

High Voltage RF GaN

Technology for Spaceborne

UHF Synthetic Aperture Radar

Applications

Gabriele Formicone, PhDIEEE Senior Member

IEEE WAD Phoenix Chapter Integra Technologies, Inc.

9-15-2016

2

1. Objectives of UHF Spaceborne SAR

2. High Efficiency Power Amplifiers

3. TCAD Design of High Voltage RF GaN

4. Measured DC & RF Results

5. Reliability Data

6. Conclusions & Further Work

OUTLINE

3

UHF Spaceborne SAR

P-band (420-450 MHz): long EM waves

penetrate foliage and ground, ideal for subsurface imaging

BIOMASS (ESA)

AirMOSS (NASA)

Objective: Multi-Mission Subsurface

Imaging Radar (MMSIR, NASA)

4

• Prime Power Budget

• Antenna / Array Size

• System Weight

• Thermal Management

• Radiation Effects

• System Cost

Space SAR constrains:

Courtesy of NASA / JPL

Space SAR enablers:• High Efficiency Power Amplifiers

• Lightweight GaN T/R Modules

• Large deployable antenna

Reference: Leopold Cantafio

Space-Based Radar Systems

and Technology, chapter 22

in Skolnik “Radar Handbook”

5

Frequency 2.385 GHz (S-band)

Peak Power 325 watts

Antenna Diameter 3.7 mPulse Length 26.5 µsPRF 4400 - 5800 HzRange ~150 mCross Range ~150 mCourtesy of NASA / JPL

Surface of Venus seen by SAR imaging

Example: Venus – Magellan Mission

6

Frequency 1215-1280 MHz (L-band)

Peak Power 500W

Antenna Diameter 6 m

Pulse Length 15 µs - PRF 2850 Hz


The L-band frequency enables observations of soil moisture through moderate vegetation cover, independent of cloud cover, at night or day.

http://smap.jpl.nasa.gov/

Example: SMAP – Soil Moisture Active Passive Mission

7


Airborne SAR to

Measure Root Zone

Soil Moisture

AirMOSS Mission Parameters

Platform altitude 12 km above terrain

Pulse width 40 us

PRF (fast) 1200 Hz

Center frequency 420 MHz

Transmit Power 1995W

http://airmoss.jpl.nasa.gov/

P-Band Example: AirMOSSAirborne Microwave Observatory of Subcanopy and Subsurface

8

BIOMASS Mission Parameters

Antenna >10 m diameter

Pulse width up to 88 us

PRF (fast) 1700 Hz

Frequency 432 - 438 MHz

Transmit Power 200W from 2x 100+ W modules

P-Band Example: BIOMASS (ESA)

Main Objective: (above) ground-cover vegetation

9

• Signal can penetrate deeper into the soil and or foliage fordetection of underground or buried structures.

• Already used by NASA/JPL on AirMOSS program (2 kW peak power) to gather data of root zone soil moisture.

• Applicable to subsurface imaging in planetary exploration.

• SBIR Phase I and II Awards to Integra Technologies, Inc. to develop

1 kW RF power module with > 70% efficiency in P-bandprogram sponsored by NASA/JPL

S1.02-9058 - A High Efficiency 1kWatt GaN

amplifier for P-Band pulsed applications

Why P-Band SAR ?

11

1 High peak Power (1 kW) needed to have good enough SNR in stronglyattenuated EM waves in lossy material (wet / moisture in soil)

2 With 1 kW peak Power need High Efficiency to fit in aircraft prime power budget; high efficiency also reduces waste heat for simpler thermal management subsystem & overall lower mission costs

3 High Power is also suitable with smaller antenna as it is hard to maneuver spacecraft with too large antenna in interplanetary mission

GaN technology is definitely an enabler for high efficiency power amplifiers and new mission concepts

NASA-MMSIR objectives are:

12

NASA-MMSIR Objective Summary:

Peak Power: 1 kWFrequency band: 420 - 450 MHz PAE: > 70% PAE Gain: > 40dBSignal: 100us, 10%Weight: < 500 gr.

13

HEPA Design Strategy

Harmonic Tuning techniques (class E, F, inverse F)

1. GaN device requires: BVDSS ≥ 3x VDD

2. Low CDS or it is hard to tune harmonics when Z is too

low

• GaN fits the bill:• Low CDS parasitic capacitances & high power density

• Wide bandgap material = radiation tolerant

DS

CCfj

Zπ2

1=

14

SBIR Phase I - approach

• Designed PA with a 24mm GaN device made by

Integra Technologies, Inc. operated at 50 V

• Achieved 160 W across 420-450 MHz band and

demonstrated > 80% drain efficiency

• HEPA design based on combination of class E and

inverse class F

15

20

21

22

23

24

25

420 430 440 450

FREQ (MHz)

Gai

n (d

B) -25C

0C

30C

55C

85C

75

77

79

81

83

85

420 430 440 450

FREQ ( MHz)

Dra

in << <<

(%)

-25C

0C

30C

55C

85C

Phase I

Measured Results

J. Custer and G. Formicone,

High Efficiency Switch-Mode

GaN-based Power Amplifiers

for P-Band Aerospace

Applications, IEEE Aerospace

Conference, March 2014.

140

150

160

170

180

420 430 440 450

FREQ (M Hz)

Psa

t (W

) -25C

0C

30C

55C

85C

16

SBIR Phase I - Results

24mm Die Measured Parameter

CDS 12pF

RDS 12.5 Ω

A. Grebennikov, N. Sokal, “Switch Mode RF Power Amplifiers,”

Elsevier, Burlington MA USA, 2007, p.164.

Ω−== 5.292

1j

CfjZ

DS

Cπ

Harmonic Inverse Class F Class E 24mm / 50 V

GaN Die

Fundamental 1 1+j0.725 1

Second ∞ -j1.785 0.12 – j 1.41

Third 0 -j1.19 0.023 – j 0.39

RF

DDBclassDSFinvDS

P

VRR

222

2

)()(

ππ==

( )Ω== 3.12

1602

50

2

2

)(W

VR FinvDS

π

17

1 kW output power met with 8x 160 W devices

However:

CDS = 8x 12 pF = 96 pF

• Load impedance gets low; harder to optimize harmonic

terminations for drain efficiency >= 80%

• Used TCAD to explore high voltage GaN transistors

optimized for RF amplifiers at 75 V and 100 V bias.

Phase I - Conclusions

Ω−== 7.32

1j

CfjZ

DS

Cπ

( )Ω==== 2

10002

50

2222

22

)()(W

V

P

VRR

RF

DDBclassDSFinvDS

πππ

18

PRF = 1000 W

VDD = 75 V → RDS = 4.4 Ω

VDD = 100 V → RDS = 7.9 Ω

VDD = 50 V → RDS = 2 Ω

Benefits of 100 V RF Devices

25x to 50 Ω

11x to 50 Ω

6x to 50 Ω

RF

DDFinvDS

P

VR

22

2

)(

π=

19

Benefits of 100 V RF DevicesHigh Voltage increases Power Density (W/mm)

and reduces gate periphery WG (and CDS, CGS,

CGD) for a given output power PRF

MAXKneeDDRF IDSVVP )(

4

1−=

−=

DD

KneeB

V

V1

4

πη 2xVDD does NOT reduce efficiency as long as

drift region does NOT increase VKnee by 2x

2xVDD requires ½ IDSMAX (or gate periphery WG) for same PRF

Longer LGD for higher VDD results in

higher RDSON and CDS, but CDG decreasesDANGER

20

0

5E-13

1E-12

1.5E-12

2E-12

2.5E-12

3E-12

-4 -3 -2 -1 0 1

VGS [V]

CG

S [

F]

0

0.2

0.4

0.6

0.8

1

1.2

1.4

0 25 50 75 100 125 150 175 200

Vds [V]

Ids [A

]

TCAD simulations of Integra’s 50 V baseline GaN process

BVDSS ≈ 135 V

TCAD Simulations

CGS ≈ 2 pF/mm

21

0

0.2

0.4

0.6

0.8

1

1.2

1.4

0 50 100 150 200 250 300 350 400

Vds [V]

Ids [A

]

TCAD simulations of Integra’s 100 V GaN process

BVDSS > 250 VTCAD Design of HV RF GaN

0.E+00

1.E-13

2.E-13

3.E-13

4.E-13

5.E-13

6.E-13

0 20 40 60 80 100

VDS [V]

C [

F] CDS

CDG

CDS ≈ 0.5 pF/mm

CDG ≈ 0.05 pF/mm

22

• Higher BVDSS is typically achieved with longer gate-drain

extension LGD

• Longer LGD leads to higher on-resistance RDSON which translates

to higher knee voltage VKnee and higher CDS

• Increased VKnee negatively impacts maximum efficiency at PSAT

which we are trying to increase by harmonic tuning techniques

• Therefore need higher BVDSS keeping RDSON and CDS small

Risk Factor with HV RF GaN

23

1. Design and build new GaN RF device operating at 75 V

(design 1) and 100 V (design 2)

2. Target single chip for 250 W across 420-450 MHz band and

demonstrate >80% drain efficiency

3. Use 2x 250 W = 500 W in a hermetic package

4. Design 1 kW HEPA module by combining 2x 500 W devices

SBIR Phase II - approach

24

Measured DC Data

100

200

300

400

500

600

700

800

3 4 5 6 7 8 9 10

DRIFT EXTENSION [um]

BV

DS

S [

V]

3e18 peak Fe

5e17 peak Fe

1e18 peak Fe

1E+16

1E+17

1E+18

1E+19

1E+20

1E+21

0 0.5 1 1.5 2

Depth (µm)

Concentr

atio

n (

Ato

ms/c

m3)

Fe

C

Analyzed GaN wafers with different Fe profile in buffer layer;C is harder to control

Data show gate-drain spacing is larger parameter to control BVDSS

but BVDSS also sensitive to Fe in buffer design and gate length

25

21 mm GaN transistor

MNM capacitor

Series chip resistor

Metal substrates & Bond Wires / Inductorsneeded to achieve high enough inductance for P-band frequencies

75 V 250 W device assembly

26

INP

UT

OU

TP

UT

50 Ω transmission lines

The shunt caps on the input are for

input impedance matching at f0 only

The shunt caps on the output

are primarily for f0 matching

The location of the shunt caps on the wide

bias line sets the 2nd and 3rd harmonic

impedance points for high efficiency

Switch-Mode Circuit Design

27

240

250

260

270

280

290

420 430 440 450

FREQUENCY (MHz)

PS

AT

(W

)

75V - LG = 0.5um 75V - LG = 1um

100V - LG = 0.5um 100V - LG = 1um

Measured RF Data

All four devices yield about the

same output power of ~250 W

PSAT vs. freq. at PIN = 2 W

20

22

24

26

28

30

420 430 440 450

FREQUENCY (MHz)

GA

IN (

dB

)75V - LG = 0.5um 75V - LG = 1um

100V - LG = 0.5um 100V - LG = 1umGAIN vs. freq. at 250 W

0.5um versus 1um yields ~3 dB

higher gain; 100 V devices have

2-3 dB higher gain than 75 V

G. Formicone and J. Custer, Mixed-Mode Class E-F-1 High Efficiency GaN Power Amplifier for P-Band Space Applications, IEEE / MTT-S IMS-2015, Phoenix, AZ.

28

71

74

77

80

83

420 430 440 450

FREQUENCY (MHz)

DR

AIN

EF

FIC

IEN

CY

(%

)

75V - LG = 0.5um 75V - LG = 1um

100V - LG = 0.5um 100V - LG = 1um

100 V devices have ~ 5% drain

efficiency points lower than 75 V

Drain Eff. vs. freq. at 250 W

Measured RF Data

-0.3

-0.25

-0.2

-0.15

-0.1

420 430 440 450

FREQUENCY (MHz)

PU

LS

E D

RO

OP

(d

B)

75V - LG = 0.5um 75V - LG = 1um

100V - LG = 0.5um 100V - LG = 1umDROOP vs. freq. at 250 W

100 V devices have worse pulse

droop than 75 V devices, most

likely due to the lower efficiency

the achieve

29

Impedance of harmonics

Measured Impedances reflect an harmonic tuning that is a combination of Class E, F and inverse F amplifier mode of operation

Class E F F-1 75V TF 100V TF

F0

1 + j 0.725 1 1 1 + j 0.15 1 + j 0.19

2 F0

- j 1.785 0 ∞ 0.11 - j 1.05 0.06 - j 0.51

3 F0

- j 1.19 ∞ 0 0.01 - j 0.42 0.03 - j 0.19

CDS = 10.5 pF - device 75 V

CDS = 7.5 pF - device 100 V

CDS ≈ 0.5 pF/mm

30

STABILITY COMPARISON WITH 2:1 VSWR MISMATCH

20

22

24

26

28

30

32

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

SPURIOUS (dBc)

GA

IN (

dB

)

1um devices have lower spurs than the ones with 0.5um gate length

which makes combining multiple chips for higher power easier in the future

GAIN vs. SPURS under VSWR mismatch

31

Select Best Design

• 75 V devices had better efficiency than the 100V ones

• 1um devices had lower spurs and better stability than the0.5um transistors under mismatch, important whencombining two chips in the package for 500 W.

• Therefore, the 75 V design with 1um gate length was chosen to design and build the 1 kW pallet

32

500 W GaN Device2x 21mm 75 V dice

Freq Class E F F-1 Normal. Z Measured Z [ΩΩΩΩ]

f0 1+j0.725 1 1 1+j0.215 8.71+j1.87

2f0 -j1.785 0 ∞∞∞∞ 0.051-j1.166 0.44-j10.16

3f0 -j1.19 ∞∞∞∞ 0 0.006-j0.057 0.05-j0.495

Freq Class E F F-1 Normal. Z Measured Z [ΩΩΩΩ]

f0 1+j0.725 1 1 1+j0.215 8.71+j1.87

2f0 -j1.785 0 ∞∞∞∞ 0.051-j1.166 0.44-j10.16

3f0 -j1.19 ∞∞∞∞ 0 0.006-j0.057 0.05-j0.495

33

+ =

4 GaN chips = 84mm

only 280g & 17cm x 9cm x 3.1cm

0.020” thick RO4350 for multipaction

Amplifier features: 1 kW, 42 dB, 75%

drain bias sequencer, TX mute, unconditional stable

G. Formicone, J. Burger, J. Custer, A UHF 1-kW Solid-State Power Amplifier for Spaceborne SAR, accepted at IEEE PAWR, Phoenix, AZ, 2017.

VISIT US at PAWR-2017 for more info

34

ReliabilityNeed to prove high voltage RF GaN is reliable enough for deployment in space!

Expectation is: high voltage RF GaN is also radiation-hard and can be space-qualified!

GaN is a wide-bandgap material

28V & 50V AlGaN/GaN HEMT technology froma few manufacturers is already space-qualified

Here we address: 1) output power stability (RF burn-in tests on 100 V devices taken at 125 V)

2) junction temperature TJ (IR measurements & modeling)

3) Load line measurements

35

RF Burn-in at VDD = 125V

-7%

-6%

-5%

-4%

-3%

-2%

-1%

0%

0 30 60 90 120 150

time [hours]

PO

UT

DE

LT

A [

%]

-0.35

-0.3

-0.25

-0.2

-0.15

-0.1

-0.05

0

DE

LT

A G

AIN

[dB

]

Pout 5e17 Pout 3e18

Pout 1e18 Gain 5e17

Gain 3e18 Gain 1e18

virgin devices

RF Burn-in

Epi with higher Fe content results in less degradation

∆POUT < 4% (0.2dB) at 125 V

G. Formicone, RF Burn-in Analysis of 100V P-band Aerospace GaN Radar Transistors, IEEE Aerospace Conference, March 2014.

36

IR Thermal Measurement

Peak TJ temperature during1ms 10% pulse is 155 °C

IR measured data on 500W 2-chip 42mm device with 85 °C case temperature

37

Thermal Modeling GaN

3”’ SiC1”’ AuSn

40”’ Package FlangeCPC flange 40mil thicknessKTH = 220 W/m-°K

A. Prejs, S. Wood, R. Pengelly and W. Pribble,

Thermal Analysis and its applications to High

Power GaN HEMT Amplifiers, 2009 IEEE MTT-S.

A. Darwish, A. J. Bayba and H. A. Hung, Channel

Temperature Analysis of GaN HEMTs With Nonlinear

Thermal Conductivity, IEEE Trans. on Electron Devices, Vol. 62, No. 3, March 2015, pp 840-845.

1.1781.178152 x 401016CPC Pkg.

2.003

0.112

0.575

0.139

RTH [°K/W]

Tcase = 26 °C

0.112152 x 4025AuSn solder

Total RTH

SiC substr.

GaN epi

Layer

2.131

0.694152 x 4075

0.147152 x 402

RTH [°K/W]

Tcase = 80 °C

Area [mil2]Thickness

[µµµµm]

1.1781.178152 x 401016CPC Pkg.

2.003

0.112

0.575

0.139

RTH [°K/W]

Tcase = 26 °C

0.112152 x 4025AuSn solder

Total RTH

SiC substr.

GaN epi

Layer

2.131

0.694152 x 4075

0.147152 x 402

RTH [°K/W]

Tcase = 80 °C

Area [mil2]Thickness

[µµµµm]

flange RTH = 55.3% of total

38

Thermal Model Calibration

Measured & Simulated Data of 500 W 75 V device with 85 °C case temperature for model calibration – TJ = 155 °C

Signal = 1ms, 10%

39

Simulated Data of 500 W 75 V device

with 85 °C case temperature for

shorter pulse width

Peak TJ temperature during

300µµµµs 10% pulse is 128 °C

Simulated Data of 500 W 75 V device

with 30 °C case temperature for

shorter pulse width



TJ in operating conditions

TJ < 150 °C during operation = good reliability

40

TJ in RF Burn-in Tests at 125 VSimulated Data of 300 W 1-chip

15mm device with 80 °C case

temperature for shorter pulse

width at 125V



Simulated Data of 350 W 1-chip

15mm device with 26 °C case

temperature for shorter pulse

width at 125V



41

CW Load Line of 2.1 mm device at 75 V

measured data on 2.1mm unit cell taken at University of Ferraracourtesy of Prof. G. Vannini, A. Raffo and G. Bosi, Dept. of Eng.

No gate – drain lagdue to traps is observed!

As VDD increases,PRF and PDISS increasehence TJ increases and IDSSAT drops!

42

CW Load Line of 1.2 mm device at >100 V

measured data on 1.2mm unit cell taken at University of Ferraracourtesy of Prof. G. Vannini, A. Raffo and G. Bosi, Dept. of Eng.

No gate – drain lagdue to traps is observed!

As VDD increases,PRF and PDISS increasehence TJ increases and IDSSAT drops!50 100 150 200 2500 300

0.1

0.2

0.3

0.4

0.5

0.6

0.0

0.7

Drain Voltage (V)

Dra

in C

urr

ent

(A)

DC I/V

Vdd = 50 V

Vdd = 75 V

Vdd = 100 V

Vdd = 150 V

Vdd = 125 V

43

Future Work&

Conclusions

44

Exploring VDD > 100 V VDD = 125V

22

23

24

25

26

27

28

29

75 125 175 225 275 325 375

POUT [W]

GA

IN [

dB

]

45

50

55

60

65

70

75

80

DR

. E

FF

IC.

[%]

5e17 Fe 3e18 Fe 1e18 Fe VDD = 150V

22

23

24

25

26

27

28

29

75 125 175 225 275 325 375 425 475

POUT [W]

GA

IN [

dB

]

40

45

50

55

60

65

70

75

DR

. E

FF

IC.

[%]

5e17 Fe 3e18 Fe 1e18 Fe

Single 15mm device at 430 MHz

G. Formicone and J. Custer, Analysis of a GaN/SiC UHF Radar Amplifier for Operation at 125V Bias, European Microwave Week Conference, Paris, Fr, 2015.

With ~ 400 W at 150 V, why not 1 kW with a single-ended device?

45

At VDD = 150 V

2x 15mm devices

operated at 150 V

150V GaN Transistor: 410 - 450 MHZ

22

23

24

25

26

27

28

29

300 400 500 600 700 800 900 1000

OUTPUT POWER [W]

GA

IN [

dB

]

30

40

50

60

70

80

90

100

DR

. E

FF

ICIE

NC

Y [

%]

GAIN - 450MHz GAIN - 430MHz

GAIN - 410MHz ETA - 450MHz

ETA - 430MHz ETA - 410MHz

800 W with > 70% drain efficiency, 410 – 450 MHz

G. Formicone, J. Burger, J. Custer and J. walker, Quest for Vacuum Tubes’ Replacement: 150 V UHF GaN Radar Transistors, European Microwave Week Conference, London, UK, 2016.

46

1 kW at VDD = 150 V 3x 15mm devices operated at 150 V > 1 kW

1 kW with > 75% drain efficiency, 420 – 450 MHz

G. Formicone, J. Burger and J. Custer, 150 V-Bias RF GaN for 1 kW UHF Radar Amplifiers, IEEE Compound Semiconductor IC Symposium, Austin, TX, 2016.

Could do 2 kW or more with

7x 15mm or larger devices in dual lead package

What about CW operation?

VISIT US at CSICS-2016 for more info

47

ISM CW Applications – 430 & 915 MHz

200 W CW, 80%, 430 MHz at 100 V

G. Formicone, J. Burger, J. Custer, G. Bosi, A. Raffo and G. Vannini, Solid-State RF Power Amplifiers for ISM CW Applications Based on 100 V GaN Technology, European Microwave Week Conference, London, UK, 2016.

15mm GaN device - 430MHz

22

23

24

25

26

27

28

50 75 100 125 150 175 200 225 250

OUTPUT POWER [W]

PO

WE

R G

AIN

[d

B]

Vdd = 75V

Vdd = 100V

Vdd = 125V

Vdd = 150V

15mm GaN device - 430MHz

35

40

45

50

55

60

65

70

75

80

85

50 75 100 125 150 175 200 225 250

OUTPUT POWER [W]

DR

AIN

EF

FIC

IEN

CY

[%

]

Vdd = 75V

Vdd = 100V

Vdd = 125V

Vdd = 150V

GaN DEVICE 1

17

17.5

18

18.5

19

19.5

20

0 20 40 60 80 100 120 140

OUTPUT POWER [W]

GA

IN [

dB

]

20

30

40

50

60

70

80

DR

. E

FF

ICIE

NC

Y [%

]

Gain; Vdd = 75V

Gain; Vdd = 50V

Dr. Eff. Vdd = 75V

Dr. Eff. Vdd = 50V

GaN DEVICE 2

15

16

17

18

19

20

0 20 40 60 80 100 120

OUTPUT POWER [W]

GA

IN [

dB

]

30

40

50

60

70

80

DR

. E

FF

ICIE

NC

Y [%

]

Gain; Vdd = 75V

Gain; Vdd = 50V

Gain; Vdd = 100V

Dr. Eff. Vdd = 75V

Dr. Eff. Vdd = 50V

Dr. Eff. Vdd = 100V

100 W CW, >60%, 915 MHz at 100 V

48

G. Formicone, J. Burger, J. Custer, W. Veitschegger, G. Bosi, A. Raffo and G. Vannini , A GaN Power Amplifier for 100 VDC Bus in GPS L-band, accepted at IEEE PAWR, Phoenix, AZ, 2017.

100 W CW at 100 V for GPS-2

L1 – band1575 ± 50 MHz

L2 – band1225 MHz

L5 – band1175 MHz

One amplifier for 3 bands!

VISIT US at PAWR-2017 for more info

49

• Developed high BVDSS RF GaN transistors for UHF pulse

radar amplifiers, but also exploring CW & other frequencies.

• Used harmonic tuning for switch-mode high efficiency PA

• Designed and built 1 kW module, TRL 4-6

• Need Phase 3 for space qualification

• What else can this technology enable? HE broadband PA?

multi-band Pas? …?

Conclusions

Assessing Official Comments “The research effort conducted by the contractor clearly shows that the

technology was viable. The contractor innovation demonstrated that the use of GaN Transistor Device for Optimum P-

Band performance can be used for Multi-Mission Subsurface Imaging Radar (MMSIR). … This technology can benefit

many areas in future radar systems. Future work is very highly recommended for SBIR contract as well as standalone

research and development contract.”

ADDITIONAL/OTHER The contract enabled Integra to develop high voltage GaN technology for multiple applications

that did not exist before.

50

Acknowledgements

Tushar Thrivikraman (Tech. Monitor)

Gregory Sadowy (Supervisor)

James Custer, PI

John Walker

Jeff Burger

51

Gabriele Formicone

Director RF Transistor Design

Integra Technologies, Inc.

[email protected]

Faculty Associate, ECEE Department

Arizona State University

[email protected]

Author Bio

Laurea in Physics, Univ. of Rome (Italy)

M.S. & Ph.D. in EE, Arizona State University

20 years experience in RF & Microwave

Device & PA Engineering

Hands-on know-how in RF LDMOS & GaN

Technologies

gabriele fmicone, phd - ieee › phoenix-wad › files › 2016 › 10 › ...sep 15, 2016 · 15...

Documents