Raytheon RF Components
362 Lowell Street
Andover, MA 01810
Revised February 6, 2003
Page 1
www.raytheonrf.com
Specifications are based on most current or latest revision.
ADVANCED INFORMATION
RF Components
RMDA20420
20-42 GHz General Purpose MMIC Amplifier
The Raytheon RF Components RMDA20420 is a broadband general purpose driver amplifier
designed for use in point to point radio, point to multi-point communications, LMDS, SatCom and
other millimeter wave applications.
The RMDA20420 is a fully matched GaAs MMIC utilizing
Raytheon RF Components' advanced 0.15
m gate length PHEMT process.
Description
Absolute
Ratings
Electrical
Characteristics
1
!
Wideband 20 - 42 GHz operation
!
22 dB small signal gain (typ.)
!
23 dBm saturated power output (typ.)
!
Matched to 50 Ohms
!
Optional bonding configuration for multiplier applications
!
Chip Size 1.720 mm x 0.760 mm
Features
Notes:
1. Operated at 25 C, 50 Ohm system, Vd=+3.5 V, quiescent current (Idq)=350 mA.
2. Typical range of the negative gate voltage is -0.9 to 0.15 V to set typical Idq of 350 mA.
3. Production measurements for small signal gain are made over a frequency range of 20 to 40 GHz.
4. Saturated power measurements are not 100% tested, but guaranteed by design.
Parameter
Symbol
Value
Unit
Positive DC Voltage (+3.5 V Typical)
Vd
+ 5
Volts
Negative DC Voltage
Vg
- 2
Volts
Simultaneous (Vd - Vg)
Vdg
+ 7
Volts
Positive DC Current
Id
600
mA
RF Input Power (from 50
source)
Pin
15
dBm
Operating Base Plate Temperature
Tc
-30 to +85
C
Storage Temperature Range
Tstg
-55 to +125
C
Thermal Resistance
Rjc
57
C/W
(Channel to Backside)
Parameter
Min
Typ
Max
Unit
Frequency Range
20
42
GHz
Drain Supply Voltage (Vd)
2
3.5
5
V
Gate Supply Voltage (Vg)
2
-2
-0.6
-0.15
V
Small Signal Gain
3
(f=20-22 GHz)
18
20
dB
(f=22-42 GHz)
20
22
dB
Gain Variation vs.
Frequency
+/-2.5
dB
Power Output at
1 dB Compression
21
dBm
Parameter
Min
Typ
Max
Unit
Power Output Saturated
4
22
23
dBm
Drain Current at
P1 dB Compression
355
mA
Drain Current at Psat
362
mA
Input Return Loss
(Pin=-20 dBm)
12
dB
Output Return Loss
(Pin=-20 dBm)
10
dB
Raytheon RF Components
362 Lowell Street
Andover, MA 01810
Revised February 6, 2003
Page 2
www.raytheonrf.com
Specifications are based on most current or latest revision.
ADVANCED INFORMATION
RF Components
RMDA20420
20-42 GHz General Purpose MMIC Amplifier
Chip Layout and
Bond Pad
Locations
Chip Size=0.0677" x
0.30" x 0.002"
(1720 m x 760 m
x 50 m)
Functional
Block Diagram
RF IN
RF OUT
Gate Supply
(2nd-4th Stages)
Drain Supply
(2nd-4th Stages)
Ground
(Back of Chip)
MMIC Chip
Vd1
Vg2 alt
Vd2
Vd3
Vd4
Vg1
Vg2
Vg3
Vg4
Drain Supply
(1st Stage)
Gate Supply
(1st Stage)
Back of Chip is RF and DC Ground
0.0065"
(0.165mm)
0.0185"
(0.465mm)
0.0125"
(0.315mm)
0.0
0.004"
(0.1mm)
0.0299"
(0.760mm)
0.0
0.004"
(0.1mm)
0.0168"
0.430mm)
0.028"
(0.715mm)
0.0475"
(1.200mm)
0.0064"
(1.620mm)
0.0677"
(1.70mm)
0.0130"
(0.335mm)
0.0275"
(0.700mm)
0.0365"
(0.930mm)
0.0465"
(1.180mm)
0.0575"
1.465mm)
0.013"
(0.330mm)
0.0249"
(0.630mm)
0.0189"
(0.480mm)
Raytheon RF Components
362 Lowell Street
Andover, MA 01810
Revised February 6, 2003
Page 3
www.raytheonrf.com
Specifications are based on most current or latest revision.
ADVANCED INFORMATION
RF Components
RMDA20420
20-42 GHz General Purpose MMIC Amplifier
Drain Supply (Vd)
(Connect to both Vd1 & Vd3)
Gate Supply (Vg)
(VGA and/or VGB)
RF IN
RF OUT
Ground
(Back of Chip)
MMIC Chip
Bond Wires Ls
Bond Wire Ls
10,000pF
100pF
Vd1
Vg2
alt
Vd2
Vd3
Vd4
Vg1
Vg2
Vg3
Vg4
100pF
10,000pF
Note: For currents > 370 mA connect
all four drain pads to the 100pF
capacitor.
Schematic of
Application
Circuit
Recommended
Assembly and
Bonding
Diagram
Vd
(Positive)
100pF
100pF
10,000pF
10,000pF
Vg
(Negative)
RF
Input
RF
Output
5mil Thick
Alumina
50-Ohm
5 mil Thick
Alumina
50-Ohm
2 mil Gap
L< 0.015"
Die-Attach
80Au/20Sn
L< 0.015"
4 places
Interchangeable Vd Bond Pads
(Do not use Vd2)
Interchangeable Vg Bond Pads
Vd1
Vg2 alt
Vd2
Vd3
Vd4
Vg1
Vg2
Vg3
Vg4
Notes:
1.
Die-attach with 80Au/20Sn
2.
Use 0.003" x 0.0005" gold ribbon for bonding.
3.
RF input and output bonds should be less than 0.015" long with stress relief.
4.
For currents > 370 mA connect all drain pads (Vd1, Vd3, & Vd4) to the 100 pF capacitor.
5.
Back of chip is DC and RF ground.
6.
Do not use Vd2 pad for drain bias connection
Note: The Input does not have a
DC blocking capacitor. It is
terminated with a 50 Ohm
resistor to ground on chip and it
is isolated from any DC bias.
Raytheon RF Components
362 Lowell Street
Andover, MA 01810
Revised February 6, 2003
Page 4
www.raytheonrf.com
Specifications are based on most current or latest revision.
ADVANCED INFORMATION
RF Components
RMDA20420
20-42 GHz General Purpose MMIC Amplifier
CAUTION:
LOSS OF GATE VOLTAGE (Vg) WHILE DRAIN VOLTAGE (Vd) IS PRESENT CAN
DAMAGE THE AMPLIFIER.
The following sequence must be followed to properly test the amplifier:
Step 1: Turn off RF input power.
Step 2: Connect the DC supply grounds to the
ground of the chip carrier.
Slowly apply negative gate bias supply
voltage of -1.5 V to Vg.
Step 3: Slowly apply positive drain bias supply
voltage of +3.5 V to Vd.
Step 4: Adjust gate bias voltage to set the
quiescent current of Idq=350 mA.
Step 5: After the bias condition is established, the
RF input signal may now be applied at the
appropriate frequency band.
Step 6: Follow turn-off sequence of:
(i) Turn off RF input power,
(ii) Turn down and off drain voltage (Vd),
(iii) Turn down and off gate bias voltage
(Vg).
Recommended
Procedure
(for biasing and
operation)
CAUTION: THIS IS AN ESD SENSITIVE DEVICE
Chip carrier material should be selected to have GaAs compatible thermal coefficient of expansion and
high thermal conductivity such as copper molybdenum or copper tungsten. The chip carrier should be
machined, finished flat, plated with gold over nickel and should be capable of withstanding 325C for 15
minutes.
Die attachment for power devices should utilize Gold/Tin (80/20) eutectic alloy solder and should avoid
hydrogen environment for PHEMT devices. Note that the backside of the chip is gold plated and is used
as RF and DC Ground.
These GaAs devices should be handled with care and stored in dry nitrogen environment to prevent
contamination of bonding surfaces. These are ESD sensitive devices and should be handled with
appropriate precaution including the use of wrist-grounding straps. All die attach and wire/ribbon bond
equipment must be well grounded to prevent static discharges through the device.
Recommended wire bonding uses 3 mils wide and 0.5 mil thick gold ribbon with lengths as short as
practical allowing for appropriate stress relief. The RF input and output bonds should be typically 0.012"
long corresponding to a typical 2 mil gap between the chip and the substrate material.
Application
Information
Raytheon RF Components
362 Lowell Street
Andover, MA 01810
Revised February 6, 2003
Page 5
www.raytheonrf.com
Specifications are based on most current or latest revision.
ADVANCED INFORMATION
RF Components
RMDA20420
20-42 GHz General Purpose MMIC Amplifier
Performance
Data
normal
amplifier
configuration
0
5
10
15
20
25
30
20
22
24
26
28
30
32
34
36
38
40
42
Frequency (GHz)
P1
d
B
(
d
B
m
)
Typical Output Power @ 1dB Compression
Bias Vd=3.5 V, Id=350 mA
Typical SS Gain Vs. Frequency Vs. Supply Current
Bias Vd=3.5
-40
-35
-30
-25
-20
-15
-10
-5
0
5
10
15
20
25
30
35
0
10
20
30
40
50
Frequency (GHz)
(d
B
)
200 mA
300 mA
350 mA
400 mA
Raytheon RF Components
362 Lowell Street
Andover, MA 01810
Revised February 6, 2003
Page 6
www.raytheonrf.com
Specifications are based on most current or latest revision.
ADVANCED INFORMATION
RF Components
RMDA20420
20-42 GHz General Purpose MMIC Amplifier
Performance
Data
Typical Input Return Loss Vs. Frequency
Bias Vd=3.5 V, Id=350 mA
Typical Output Return Loss Vs. Frequency
Bias Vd=3.5 V, Id=350 mA
-60
-50
-40
-30
-20
-10
0
0
10
20
30
40
50
Frequency (GHz)
(d
B
)
-35
-30
-25
-20
-15
-10
-5
0
0
10
20
30
40
50
Frequency (GHz)
(d
B
)
Raytheon RF Components
362 Lowell Street
Andover, MA 01810
Revised February 6, 2003
Page 7
www.raytheonrf.com
Specifications are based on most current or latest revision.
ADVANCED INFORMATION
RF Components
RMDA20420
20-42 GHz General Purpose MMIC Amplifier
Performance
Data
Typical SS Gain Vs. Frequency Vs. Base Plate
Temperature
Bias Vd=3.5 V, Id=350 mA
Typical SS Gain Vs. Frequency Vs. Supply Voltage
Supply Current=350 mA
-30
-20
-10
0
10
20
30
40
0
10
20
30
40
50
Frequency (GHz)
S2
1
(
d
B
)
90 C
20 C
-40 C
-40
-30
-20
-10
0
10
20
30
40
0
10
20
30
40
50
Frequency (GHz)
(d
B
)
Vds=5.0
Vds=3.5
Vds=2.0
Raytheon RF Components
362 Lowell Street
Andover, MA 01810
Revised February 6, 2003
Page 8
www.raytheonrf.com
Specifications are based on most current or latest revision.
ADVANCED INFORMATION
RF Components
RMDA20420
20-42 GHz General Purpose MMIC Amplifier
Performance
Data
17
19
21
23
25
27
15
17
19
21
23
Output Pow er (dBm)
Ga
i
n
(
d
B)
0%
4%
8%
12%
16%
20%
PA
E
(
%
)
PAE
Gain
17
19
21
23
25
27
15
17
19
21
23
O u tp u t P o w er (d Bm )
Ga
i
n
(
d
B
)
0%
4%
8%
12%
16%
20%
PAE
(
%
)
P AE
G ain
Gain Compression and PAE Vs. Output Power
Frequency=30 GHz, Bias Vd=3.5 V, Id=350 mA
Gain Compression and PAE Vs. Output Power
Frequency=40 GHz, Bias Vd=3.5 V, Id=350 mA
Raytheon RF Components
362 Lowell Street
Andover, MA 01810
Revised February 6, 2003
Page 9
www.raytheonrf.com
Specifications are based on most current or latest revision.
ADVANCED INFORMATION
RF Components
RMDA20420
20-42 GHz General Purpose MMIC Amplifier
Performance
Data
5
6
7
8
9
10
11
12
13
14
15
20
22
24
26
28
30
32
34
36
38
40
F req u en cy (G Hz)
N
o
i
s
e
F
i
gur
e
(
dB
)
Id q = 100 m A
Id q = 200 m A
Id q = 350 m A
5
6
7
8
9
10
11
12
13
14
15
20
22
24
26
28
30
32
34
36
38
40
Frequency (GHz)
N
o
is
e
F
ig
u
r
e
(
d
B
)
Vd= 5.0
Vd= 4.5
Vd= 2.0
Vd= 3.5
Noise Figure Vs. Frequency Vs. Supply Current
Bias Vd=3.5 Volts
Noise Figure Vs. Frequency Vs. Supply Voltage
Supply Current=200mA
Raytheon RF Components
362 Lowell Street
Andover, MA 01810
Revised February 6, 2003
Page 10
www.raytheonrf.com
Specifications are based on most current or latest revision.
ADVANCED INFORMATION
RF Components
RMDA20420
20-42 GHz General Purpose MMIC Amplifier
Application
Information
multiplier
operation
The RMDA20420 can be used as an even harmonic multiplier or as an odd harmonic multiplier
depending on the type of DC biasing arrangement being used. Optimum DC bias is applied to peak the
desired harmonic which falls into the 20 to 42 GHz passband. The following application information will
detail the configuration and procedure for using the RMDA20420 as an even harmonic multiplier and
as an odd harmonic multiplier. Typical measured data is provided at selected frequencies within the
passband with the RMDA20420 configured as a doubler and as a tripler.
Multiplier Operation
The Raytheon RMDA20420 is a four stage general purpose MMIC amplifier covering the 20-42 GHz
passband. The amplifier has a steep gain roll off at the band edges and the input return loss of the
amplifier is better than 10 dB from 42 GHz down to DC. Any multiplier harmonics, which fall in the
passband, will get amplified and any harmonics that fall below the passband will get suppressed.
A deliberate design feature that makes the RMDA20420 an effective multiplier is the ability to
independently bias the first stage. This feature allows freedom to determine the optimum DC bias
condition required to peak the desired harmonic and suppressing the unwanted harmonics. Optimum
DC bias conditions depend largely on factors such as fundamental frequency, desired harmonic
frequency, input power level, output power level and suppression requirements.
Test Set Up
The basic test set uses a source to provide the input signal at the desired frequency and power level.
The DUT was biased either as an even harmonic or odd harmonic operation and the output was
observed on a spectrum analyzer. The power of the harmonics was measured using the spectrum
analyzer with all the cable losses accounted. Figure 1 shows the basic test set used.
DUT
Source
Spectrum Analyzer
RMDA20420
Figure 1. Basic test set up.
Raytheon RF Components
362 Lowell Street
Andover, MA 01810
Revised February 6, 2003
Page 11
www.raytheonrf.com
Specifications are based on most current or latest revision.
ADVANCED INFORMATION
RF Components
RMDA20420
20-42 GHz General Purpose MMIC Amplifier
Even Harmonic Operation
Even harmonics are generated whenever the symmetry of the input signal waveform is distorted. This
is accomplished by biasing the first stage operating point in a region of the I-V curve where the device
is near pinch-off. In this condition, the first stage becomes a half wave rectifier where conduction only
occurs on positive half cycles of the input waveform. Thus, presenting an asymmetrical waveform
consisting mainly of positive half cycles which is rich in even harmonics to the remaining stages of the
amplifier.
For most even harmonic multiplier operations, the first stage is usually pinched off and the remaining
stages are biased as a linear amplifier. As an example, the RMDA20420 was evaluated as a doubler.
In the doubler operation, two drain voltages of +3.5V were used: One for first stage (Vd1) and the other
(Vd2) for the remaining 3 stages tied together as shown in Figure 2. Independent biasing of the first
stage was achieved by using two separate gate voltages. Vg1 was used for stage one and set to Vg1=-
1.0V (near pinch-off). Vg2 was used for the remaining three stages. Vg2 was adjusted until Idq=330mA.
For each input frequency and input power level, Vg1 was adjusted to peak the second harmonic. Small
changes in Vg2 and Vd2 at this point help in suppressing odd harmonics. Figure 3 shows the doubler
performance over the 20 to 42 GHz band for a fixed input power level of +12 dBm. The graph shows
doubled frequencies with output power levels greater than +16dBm over the 20-42 GHz band. The
graph also shows the increasing power level of the fundamental at the higher end of the band since the
fundamental frequency approaches the lower band edge of the amplifier passband. Based on these
measurements the RMDA20420 can be used a doubler to give desired frequencies anywhere in the 20-
42 GHz band with a conversion gain up to 8 dB and second harmonic power levels up to 20 dBm.
RF IN
RF OUT
Vg2
Vd2
Vd1
Vg2 alt
Vd2
Vd3
Vd4
Vg1
Vg2
Vg3
Vg4
Vd1
Vg1
Figure 2. RMDA20420 configured as doubler.
Application
Information
multiplier
operation
Raytheon RF Components
362 Lowell Street
Andover, MA 01810
Revised February 6, 2003
Page 12
www.raytheonrf.com
Specifications are based on most current or latest revision.
ADVANCED INFORMATION
RF Components
RMDA20420
20-42 GHz General Purpose MMIC Amplifier
Conversion
Gain = 0
2 x Fo
1 x Fo
-30
-20
-10
0
10
20
30
20
22
24
26
28
30
32
34
36
38
40
42
Second Harmonic Frequency (GHz)
P
out
(dB
m
)
RF IN
RF OUT
Vd1
Vg2 alt
Vd2
Vd3
Vd4
Vg1
Vg2
Vg3
Vg4
Vd1
Vg1
Figure 3. Measured Doubler Performance.
Odd Harmonic Operation
Odd harmonics are generally associated with a square wave. The RMDA20420 is biased in such a way
that causes the clipping of the input sine wave to closely approximate a square wave provided a high
input drive level is maintained. If biased in a manner, which causes the input waveform to be clipped
equally in the positive and negative cycles, then a symmetrical square wave will be approximated which
contains odd harmonics.
As an example, the RMDA20420 was biased as a tripler over the 20-40GHz band at selected
frequencies. In this mode of operation all the drains voltages (Vd1 and Vd2) were tied together and all
the gate voltages were tied together as shown in Figure 4.
Figure 4. RMDA20420 configured as tripler.
Application
Information
multiplier
operation
Raytheon RF Components
362 Lowell Street
Andover, MA 01810
Revised February 6, 2003
Page 13
www.raytheonrf.com
Specifications are based on most current or latest revision.
ADVANCED INFORMATION
RF Components
RMDA20420
20-42 GHz General Purpose MMIC Amplifier
The test set up for this mode of operation is as shown in Figure 1.The biasing procedure requires the
gate voltage Vg1 to be initially set to 1.0V. Next the drain voltage Vd1 was set to +2.0V. The input
frequency was selected to give the desired tripled output and the input drive level was set to +14dBm.
The output of the RDMA20420 was observed and the harmonics of the input frequency were visible on
the spectrum analyzer display. The gate voltage Vg1 was adjusted gradually to peak the third harmonic.
Lowering Vg1 resulted in peaking the third harmonic. Then the drain voltage Vd1 was adjusted to tweak
the power level of the third harmonic. Tweaking Vg1 and Vd1 at this point resulted in further
optimization of the desired harmonic or suppression of the unwanted harmonic as required. The range
for Vg1 was between 0.1 to 0.6V and the range for Vd1 was between +1.1 to +1.8V. The above
procedure was repeated for each input frequency tested.
Figure 5 shows the tripled output for the RMDA20420 biased as described above. Input frequencies
were selected to give tripled frequencies falling in the 21 to 39 GHz band. The graph shows tripled
output powers greater than +10dBm up to 39 GHz. The power levels of the first and second harmonics
were also plotted to show the level of suppression of the unwanted harmonics. The graph shows for a
tripled frequency of 30 GHz the output power was +14 dBm, the fundamental (10GHz) power level was
17 dBm and the second harmonic (20 GHz) power level was +3 dBm. The conversion gain for the
tripled output at 30GHz was 0dB. For tripled frequencies between 21 to 39GHz, the conversion gain
was better than 4 dB.
1xFo
39GHz
30GHz
21GHz
-20
-15
-10
-5
0
5
10
15
20
20
22
24
26
28
30
32
34
36
38
40
Tripled Frequency (GHz)
P
out
(dB
m
)
2xFo
3xFo
Conversion
Gain =0
Figure 5. Measured Tripler Performance.
Application
Information
multiplier
operation
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