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Optimum Technology Matching® Applied
GaAs HBT
InGaP HBT
GaAs MESFET
SiGe BiCMOS
Si BiCMOS
SiGe HBT
GaAs pHEMT
Si CMOS
Si BJT
GaN HEMT
Functional Block Diagram
RF MICRO DEVICES®, RFMD®, Optimum Technology Matching®, Enabling Wireless Connectivity™, PowerStar®, POLARIS™ TOTAL RADIO™ and UltimateBlue™ are trademarks of RFMD, LLC. BLUETOOTH is a trade-
mark owned by Bluetooth SIG, Inc., U.S.A. and licensed for use by RFMD. All other trade names, trademarks and registered trademarks are the property of their respective owners. ©2012, RF Micro Devices, Inc.
Product Description
7628 Thorndike Road, Greensboro, NC 27409-9421 · For sales or technical
support, contact RFMD at (+1) 336-678-5570 or customerservice@rfmd.com.
Ordering Information
BiFET HBT
RF IN
VGQ
Pin 1 (CUT)
RF OUT
VDQ
Pin 2
GND
BASE
RF3931
30W GaN WIDEBAND POWER AMPLIFIER
The RF3931 is a 48V 30W high power discrete amplifier designed for commercial
wireless infrastructure, cellular and WiMAX infrastructure, industrial/scien-
tific/medical, and general purpose broadband amplifier applications. Using an
advanced high power density Gallium Nitride (GaN) semiconductor process, these
high-performance amplifiers achieve high efficiency and flat gain over a broad fre-
quency range in a single amplifier design. The RF3931 is an unmatched GaN tran-
sistor packaged in a hermetic, flanged ceramic package. This package provides
excellent thermal stability through the use of advanced heat sink and power dissi-
pation technologies. Ease of integration is accomplished through the incorporation
of simple, optimized matching networks external to the package that provide wide-
band gain and power performance in a single amplifier.
Features
Broadband Operation DC to
3.5GHz
Advanced GaN HEMT
Technology
Advanced Heat-Sink
Technology
Gain = 15dB at 2GHz
48V Operation Typical
Performance at 900MHz
• Output Power 50W
•Drain Efficiency 65%
• -40°C to 85°C Operation
Applications
Commercial Wireless
Infrastructure
Cellular and WiMAX
Infrastructure
Civilian and Military Radar
General Purpose Broadband
Amplifiers
Public Mobile Radios
Industrial, Scientific and
Medical
RF3931S2 2-Piece sample bag
RF3931SB 5-Piece bag
RF3931SQ 25-Piece bag
RF3931SR 100 Pieces on 7” short reel
RF3931TR7 750 Pieces on 7” reel
RF3931PCK-411 Fully assembled evaluation board optimized for 2.14GHz; 48V
DS120406
Package Style: Hermetic 2-Pin Flanged Ceramic
2 of 14
RF3931
DS120406
7628 Thorndike Road, Greensboro, NC 27409-9421 · For sales or technical
support, contact RFMD at (+1) 336-678-5570 or customerservice@rfmd.com.
Absolute Maximum Ratings
Parameter Rating Unit
Drain Voltage (VD)150V
Gate Voltage (VG) -8 to +2 V
Gate Current 23 mA
Operational Voltage 65 V
Ruggedness (VSWR) 10:1
Storage Temperature Range -55 to +125 °C
Operating Temperature Range (TL)-40 to +85°C
Operating Junction Temperature (TJ) 200 °C
Human Body Model Class 1A
MTTF (TJ < 200°C, 95% Confidence Limits)* 3 x 106hours
Thermal Resistance, RTH(junction to case)
measured at TC = 85°C, DC bias only
3.6 °C/W
*MTTF - median time to failure for wear-out failure mode (30%ldss
degradation) which is determined by the technology reliability. Refer to
product qualification report for FIT (random) Failure rate.
Operation of this device beyond any one of these limits may cause permanent
damage. For reliable continuous operation, the device voltage and current
must not exceed the maximum operating values specified in the table on page
two.
Bias Conditions should also satisfy the following expression:
PDISS < (TJ – TC) / RTH J-C and TC = TCASE
Parameter Specification Unit Condition
Min. Typ. Max.
Recommended Operating Conditions
Drain Voltage (VDSQ)2848V
Gate Voltage (VGSQ)-5-3-2.5V
Drain Bias Current 130 mA
Frequency of Operation DC 3500 MHz
Capacitance
CRSS 4pFV
G = -8V, VD = 0V
CISS 17 pF VG = -8V, VD = 0V
COSS 12 pF VG = -8V, VD = 0V
DC Function Test
IG (OFF) - Gate Leakage 2 mA VG = -8V, VD = 0V
ID (OFF) - Drain Leakage 2.5 mA VG = -8V, VD = 48V
VGS (TH) - Threshold Voltage -4.2 V VG = -8V, ID = 6.6mA
VDS (ON) - Drain Voltage at high current 0.25 V VG = 0V, ID = 1.5A
RF Function Test [1],[2]
VGS (Q) -3.5 V VD = 48V, ID = 130mA
Gain 10 12 dB CW, POUT = 45.8dBm, f = 2140MHz
Drain efficiency 55 60 % CW, POUT = 45.8dBm, f = 2140MHz
Input Return Loss -12 -10 dB CW, POUT = 45.8dBm, f = 2140MHz
Caution! ESD sensitive device.
Exceeding any one or a combination of the Absolute Maximum Rating conditions may
cause permanent damage to the device. Extended application of Absolute Maximum
Rating conditions to the device may reduce device reliability. Specified typical perfor-
mance or functional operation of the device under Absolute Maximum Rating condi-
tions is not implied.
The information in this publication is believed to be accurate and reliable. However, no
responsibility is assumed by RF Micro Devices, Inc. ("RFMD") for its use, nor for any
infringement of patents, or other rights of third parties, resulting from its use. No
license is granted by implication or otherwise under any patent or patent rights of
RFMD. RFMD reserves the right to change component circuitry, recommended appli-
cation circuitry and specifications at any time without prior notice.
RFMD Green: RoHS compliant per EU Directive 2002/95/EC, halogen free
per IEC 61249-2-21, < 1000ppm each of antimony trioxide in polymeric
materials and red phosphorus as a flame retardant, and <2% antimony in
solder.
3 of 14
RF3931
DS120406
7628 Thorndike Road, Greensboro, NC 27409-9421 · For sales or technical
support, contact RFMD at (+1) 336-678-5570 or customerservice@rfmd.com.
Parameter Specification Unit Condition
Min. Typ. Max.
RF Typical Performance [1],[2]
Small Signal Gain 20 dB CW, f = 900MHz
Small Signal Gain 14 dB CW, f = 2140MHz
Output Power at P3dB 47 dBm CW, f = 900MHz
Output Power at P3dB 46.5 dBm CW, f = 2140MHz
Drain Efficiency at P3dB 65 % CW, f = 900MHz
Drain Efficiency at P3dB 65 % CW, f = 2140MHz
[1] Test Conditions: CW Operation, VDSQ = 48V, IDQ = 130mA, T = 25°C
[2] Performance in a standard tuned test fixture
4 of 14
RF3931
DS120406
7628 Thorndike Road, Greensboro, NC 27409-9421 · For sales or technical
support, contact RFMD at (+1) 336-678-5570 or customerservice@rfmd.com.
Typical Performance in standard 2.14GHz fixed tuned test fixture
(CW, T = 25°C, unless noted)
-25
-23
-21
-19
-17
-15
-13
-11
-9
-7
-5
6
7
8
9
10
11
12
13
14
15
16
2080 2110 2140 2170 2200
Input Return Loss (dB)
Gain (dB)
Frequency (MHz)
Small Signal Performance vs. Frequency, Pout = 30dBm
(Vd = 48V, Idq = 130mA)
Gain IRL
Fixed tuned test circuit
-25
-23
-21
-19
-17
-15
-13
-11
-9
-7
-5
5
6
7
8
9
10
11
12
13
14
15
2080 2100 2120 2140 2160 2180 2200
Input Return Loss (dB)
Gain (dB)
Frequency (MHz)
Gain/IRL vs. Frequency, Pout = 46dBm
(CW, Vd = 48V, Idq = 130mA)
Gain IRL
Fixed tuned test circuit
50
52
54
56
58
60
2080 2100 2120 2140 2160 2180 2200
Drain Efficiency (%)
Frequency (MHz)
Drain Efficiency vs. Frequency, Pout = 46dBm
(CW, Vd = 48V, Idq = 130mA)
Eff
Fixed tuned test circuit
5 of 14
RF3931
DS120406
7628 Thorndike Road, Greensboro, NC 27409-9421 · For sales or technical
support, contact RFMD at (+1) 336-678-5570 or customerservice@rfmd.com.
0
10
20
30
40
50
60
70
2
4
6
8
10
12
14
16
29 31 33 35 37 39 41 43 45 47
Drain Efficiency (%)
Gain (dB)
Pout, Output Power (dBm)
Gain/ Efficiency vs. Pout, f = 2140MHz
(CW, Vd = 48V, Idq = 130mA)
Gain
Drain Eff
0
10
20
30
40
50
60
70
2
4
6
8
10
12
14
16
30 32 34 36 38 40 42 44 46
Drain Efficiency (%)
Gain (dB)
Pout, Output Power (dBm)
Gain/ Efficiency vs. Pout, f = 2140MHz
(Pulsed 10% duty cycle, 10uS, Vd = 48V, Idq = 130mA)
Gain
Drain Eff
-50
-45
-40
-35
-30
-25
-20
-15
-10
001011
IMD3, Intermodulaon Distoron (dBc)
Pout, Output Power (W-PEP)
IMD3 vs. Pout
(2-Tone 1MHz Seperaon, Vd = 48V, Idq varied, fc = 2140MHz)
65mA
100mA
130mA
260mA
390mA
10
11
12
13
14
15
16
17
18
0
0
1
011
Gain (dB)
Pout, Output Power (W-PEP)
Gain vs. Pout
(2-Tone 1MHz Seperaon, Vd = 48V, Idq varied, fc = 2140MHz)
65mA
100mA
130mA
260mA
390mA
-70
-60
-50
-40
-30
-20
-10
0
0
0
10
11
Intermodulaon Distoron (IMD - dBc)
Pout, Output Power (W-PEP)
IMD vs. Output Power
(Vd = 48V, Idq = 130mA, f1 = 2139.5MHz, f2 = 2140.5MHz)
-IMD3 IMD3
-IMD5 IMD5
-IMD7 IMD7
6 of 14
RF3931
DS120406
7628 Thorndike Road, Greensboro, NC 27409-9421 · For sales or technical
support, contact RFMD at (+1) 336-678-5570 or customerservice@rfmd.com.
Typical Performance in standard 900MHz fixed tuned test fixture
(CW, T = 25°C, unless noted)
-10
-9
-8
-7
-6
-5
-4
-3
-2
-1
0
12
13
14
15
16
17
18
19
20
21
22
880 890 900 910 920
Input Return Loss (dB)
Gain (dB)
Frequency (MHz)
Small Signal Performance vs. Frequency, Pout = 30dBm
(Vd = 48V, Idq = 130mA)
Gain IRL
Fixed tuned test circuit
-10
-9
-8
-7
-6
-5
-4
-3
-2
-1
0
12
13
14
15
16
17
18
19
20
21
22
880 890 900 910 920
Input Return Loss (dB)
Gain (dB)
Frequency (MHz)
Gain/IRL vs. Frequency, Pout = 47dBm
(CW, Vd = 48V, Idq = 130mA)
Gain IRL
Fixed tuned test circuit
0
10
20
30
40
50
60
70
14
15
16
17
18
19
20
21
22
29 31 33 35 37 39 41 43 45 47
Drain Efficiency (%)
Gain (dB)
Pout, Output Power (dBm)
Gain/ Efficiency vs. Pout, f = 900MHz
(CW, Vd = 48V, Idq = 130mA)
Gain
Drain Eff
7 of 14
RF3931
DS120406
7628 Thorndike Road, Greensboro, NC 27409-9421 · For sales or technical
support, contact RFMD at (+1) 336-678-5570 or customerservice@rfmd.com.
15
16
17
18
19
20
21
22
001
011
Gain (dB)
Pout, Output Power (W-PEP)
Gain vs. Pout
(2-Tone 1MHz Seperaon, Vd = 48V, Idq varied, fc = 900MHz)
65mA
100mA
130mA
260mA
390mA
-60
-50
-40
-30
-20
-10
0
001011
Intermodulaon Distoron (IMD - dBc)
Pout, Output Power (W- PEP)
IMD vs. Output Power
(Vd = 48V, Idq = 130mA, f1 = 899.5MHz, f2 = 900.5MHz)
-IMD3 IMD3
-IMD5 IMD5
-IMD7 IMD7
-50
-45
-40
-35
-30
-25
-20
-15
-10
001011
IMD3, Intermodulaon Distoron (dBc)
Pout, Output Power (W-PEP)
IMD3 vs. Pout
(2-Tone 1MHz Seperaon, Vd = 48V, Idq varied, fc = 900MHz)
65mA
100mA
130mA
260mA
390mA
8 of 14
RF3931
DS120406
7628 Thorndike Road, Greensboro, NC 27409-9421 · For sales or technical
support, contact RFMD at (+1) 336-678-5570 or customerservice@rfmd.com.
Package Drawing
(Package Style: Flanged Ceramic)
Pin Function Description
1 Gate Gate - VG RF Input
2 Drain Drain - VD RF Output
3 Source Source - Ground Base
9 of 14
RF3931
DS120406
7628 Thorndike Road, Greensboro, NC 27409-9421 · For sales or technical
support, contact RFMD at (+1) 336-678-5570 or customerservice@rfmd.com.
Bias Instruction for RF3931 Evaluation Board
ESD Sensitive Material. Please use proper ESD precautions when handling devices of evaluation board.
Evaluation board requires additional external fan cooling.
Connect all supplies before powering up the evaluation board.
1. Connect RF cables at RFIN and RFOUT.
2. Connect ground to the ground supply terminal, and ensure that both the VG and VD grounds are also connected to this
ground terminal.
3. Apply -8V to VG.
4. Apply 48V to VD.
5. Increase VG until drain current reaches 130mA desired bias point.
6. Turn on the RF input.
10 of 14
RF3931
DS120406
7628 Thorndike Road, Greensboro, NC 27409-9421 · For sales or technical
support, contact RFMD at (+1) 336-678-5570 or customerservice@rfmd.com.
2.14GHz Evaluation Board Schematic
2.14GHz Evaluation Board Bill of Materials
Component Value Manufacturer Part Number
C1, C2, C10, C11 33pF ATC ATC800A330JT
C3,C14 0.1F Murata GRM32NR72A104KA01L
C4,C13 4.7F Murata GRM55ER72A475KA01L
C5 100F Panasonic ECE-V1HA101UP
C6 2.2pF ATC ATC800A2R2BT
C7 0.7pF ATC ATC800A0R7BT
C8 1.0pF ATC ATC800A1R0BT
C9 3.3pF ATC ATC800A3R3BT
C12 100F Panasonic EEV-TG2A101M
C15 10pF ATC ATC800A100JT
R1 10Panasonic ERJ-8GEYJ100V
C16, C17, C18, C19 Not used - -
PCB RO4350, 0.030" thick
dielectric
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11 of 14
RF3931
DS120406
7628 Thorndike Road, Greensboro, NC 27409-9421 · For sales or technical
support, contact RFMD at (+1) 336-678-5570 or customerservice@rfmd.com.
2.14GHz Evaluation Board Layout
Device Impedances
Note: Device impedances reported are the measured evaluation board impedances chosen for a trade off of efficiency, peak power, and linearity
performance across the entire frequency bandwidth.
Frequency (MHz) Z Source ()Z Load (
2110 2.6 - j3.1 6.5 + j5.8
2140 2.5 - j2.8 6.7 + j6.6
2170 2.4 - j2.5 7.0 + j7.4
12 of 14
RF3931
DS120406
7628 Thorndike Road, Greensboro, NC 27409-9421 · For sales or technical
support, contact RFMD at (+1) 336-678-5570 or customerservice@rfmd.com.
900MHz Evaluation Board Schematic
900MHz Evaluation Board Bill of Materials
Component Value Manufacturer Part Number
C1, C2, C10, C11 68pF ATC ATC800B680JT
C3,C14 0.1F Murata GRM32NR72A104KA01L
C4,C13 4.7F Murata GRM55ER72A475KA01L
C5 100F Panasonic ECE-V1HA101UP
C6 12pF ATC ATC800B120
C7 5.6pF ATC ATC800B5R6
C8 6.8pF ATC ATC800B6R8
C9 2.0pF ATC ATC800B2R0
C12 330F Panasonic EEU-FC2A331
R1 10Panasonic ERJ-8GEYJ100V
RF3931
C6
R1
C1C3C4C5
+
VGATE VDRAIN
C13C14
C11 C12
+
C7
C2
C10
50 strip 50 strip
J1
RF IN
J2
RF OUT
C8 C9
13 of 14
RF3931
DS120406
7628 Thorndike Road, Greensboro, NC 27409-9421 · For sales or technical
support, contact RFMD at (+1) 336-678-5570 or customerservice@rfmd.com.
900MHz Evaluation Board Layout
Device Impedances
Note: Device impedances reported are the measured evaluation board impedances chosen for a trade off of efficiency, peak power, and linearity
performance across the entire frequency bandwidth.
Loadpull contours available on RFMD website.
Frequency (MHz) Z Source ()Z Load (
880 4.2 + j9.0 12.9 + j14.2
900 4.3 + j10.0 13.6 + j15.1
920 4.4 + j11.3 14.4 + j16.0
14 of 14
RF3931
DS120406
7628 Thorndike Road, Greensboro, NC 27409-9421 · For sales or technical
support, contact RFMD at (+1) 336-678-5570 or customerservice@rfmd.com.
Device Handling/Environmental Conditions
GaN HEMT devices are ESD sensitive materials. Please use proper ESD precautions when handling devices or
evaluation boards.
GaN HEMT Capacitances
The physical structure of the GaN HEMT results in three terminal capacitors similar to other FET technologies.
These capacitances exist across all three terminals of the device. The physical manufactured characteristics of
the device determine the value of the CDS (drain to source), CGS (gate to source) and CGD (gate to drain). These
capacitances change value as the terminal voltages are varied. RFMD presents the three terminal capacitances
measured with the gate pinched off (VGS = -8V) and zero volts applied to the drain. During the measurement pro-
cess, the parasitic capacitances of the package that holds the amplifier is removed through a calibration step.
Any internal matching is included in the terminal capacitance measurements. The capacitance values presented
in the typical characteristics table of the device represent the measured input (CISS), output (COSS), and reverse
(CRSS) capacitance at the stated bias voltages. The relationship to three terminal capacitances is as follows:
CISS = CGD + CGS
COSS = CGD + CDS
CRSS = CGD
DC Bias
The GaN HEMT device is a depletion mode high electron mobility transistor (HEMT). At zero volts VGS the drain of
the device is saturated and uncontrolled drain current will destroy the transistor. The gate voltage must be taken
to a potential lower than the source voltage to pinch off the device prior to applying the drain voltage, taking care
not to exceed the gate voltage maximum limits. RFMD recommends applying VGS = -5V before applying any VDS.
RF Power transistor performance capabilities are determined by the applied quiescent drain current. This drain
current can be adjusted to trade off power, linearity, and efficiency characteristics of the device. The recom-
mended quiescent drain current (IDQ) shown in the RF typical performance table is chosen to best represent the
operational characteristics for this device, considering manufacturing variations and expected performance.
The user may choose alternate conditions for biasing this device based on performance trade off.
Mounting and Thermal Considerations
The thermal resistance provided as RTH (junction to case) represents only the packaged device thermal charac-
teristics. This is measured using IR microscopy capturing the device under test temperature at the hottest spot of
the die. At the same time, the package temperature is measured using a thermocouple touching the backside of
the die embedded in the device heatsink but sized to prevent the measurement system from impacting the
results. Knowing the dissipated power at the time of the measurement, the thermal resistance is calculated.
In order to achieve the advertised MTTF, proper heat removal must be considered to maintain the junction at or
below the maximum of 200°C. Proper thermal design includes consideration of ambient temperature and the
thermal resistance from ambient to the back of the package including heatsinking systems and air flow mecha-
nisms. Incorporating the dissipated DC power, it is possible to calculate the junction temperature of the device.