Gabriele Fmicone, PhD - IEEE › phoenix-wad › files › 2016 › 10 › ...Sep 15, 2016 · 15...
Transcript of Gabriele Fmicone, PhD - IEEE › phoenix-wad › files › 2016 › 10 › ...Sep 15, 2016 · 15...
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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
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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
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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)
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• 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”
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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
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Frequency 1215-1280 MHz (L-band)
Peak Power 500W
Antenna Diameter 6 m
Pulse Length 15 µs - PRF 2850 Hz
Courtesy of NASA / JPL
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
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Courtesy of NASA / JPL
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
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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
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• 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 ?
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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:
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NASA-MMSIR Objective Summary:
Peak Power: 1 kWFrequency band: 420 - 450 MHz PAE: > 70% PAE Gain: > 40dBSignal: 100us, 10%Weight: < 500 gr.
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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=
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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
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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
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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
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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
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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=
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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
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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
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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
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• 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
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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
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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
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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
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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
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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.
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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
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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
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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
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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
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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
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+ =
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
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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
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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.
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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
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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
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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%
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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
Peak TJ temperature during
300µµµµs 10% pulse is 66 °C
TJ in operating conditions
TJ < 150 °C during operation = good reliability
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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
Peak TJ temperature during
100µµµµs 10% pulse is 150 °C
Simulated Data of 350 W 1-chip
15mm device with 26 °C case
temperature for shorter pulse
width at 125V
Peak TJ temperature during
100µµµµs 10% pulse is 84 °C
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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!
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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
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Future Work&
Conclusions
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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?
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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.
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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
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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
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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
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• 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.
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Acknowledgements
Tushar Thrivikraman (Tech. Monitor)
Gregory Sadowy (Supervisor)
James Custer, PI
John Walker
Jeff Burger
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Gabriele Formicone
Director RF Transistor Design
Integra Technologies, Inc.
Faculty Associate, ECEE Department
Arizona State University
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