MGA-87563
0.5–4 GHz 3 V Low Current
GaAs MMIC LNA
Data Sheet
Description
Avago’s MGA-87563 is an economical, easy-to-use GaAs
MMIC amplifier that offers low noise and excellent gain
for applications from 0.5 to 4 GHz. Packaged in an ultra-
miniature SOT-363 package, it requires half the board
space of a SOT-143 package.
With the addition of a simple shunt-series inductor at the
input, the device is easily matched to achieve a noise of
1.6 dB at 2.4 GHz. For 2.4 GHz applications and above, the
output is well matched to 50 Ohms. Below 2 GHz, gain
can be increased by using conjugate matching.
The circuit uses state-of-the-art PHEMT technology with
self-biasing current sources, a source-follower interstage,
resistive feedback, and on-chip impedance matching
networks. A patented, on-chip active bias circuit allows
operation from a single +3 V or +5 V power supply. Cur-
rent consumption is only 4.5 mA, making this part ideal
for battery powered designs.
Features
x
Lead-free Option Available
x
Ultra-Miniature Package
x
1.6 dB Min. Noise Figure at 2.4 GHz
x
12.5 dB Gain at 2.4 GHz
x
Single +3 V or 5 V Supply, 4.5 mA Current
Applications
x
LNA or Gain Stage for PCS, ISM, Cellular, and GPS
Applications
Equivalent Circuit
6
RF
INPUT
3
4
V
dd
RF
OUTPUT
Surface Mount SOT-363 (SC-70) Package
GROUND
1, 2,
5
Pin Connections and Package Marking
87x
GND
GND
INPUT
1
2
3
6
5
4
OUTPUT
GND
V
dd
Attention: Observe precautions for
handling electrostatic sensitive devices.
ESD Human Body Model (Class 0)
Refer to Avago Application Note A004R:
Electrostatic Discharge Damage and Control.
Note:
Package marking provides orientation and identification.
"87" = Device Code
"x" = Date code character identifies month of manufacture
MGA-87563 Typical Performance,
T
C
= 25°C, V
dd
= 3 V
5
20
0
ASSOCIATED GAIN (dB)
4
NOISE
FIGURE (dB)
15
-1
3
+85
2
+25
1
-40
P
1 dB
(dBm)
10
-40
+25
+85
-2
-40
+25
+85
-3
5
-4
0
0.5
1.0
1.5
2.0
2.5
3.0
3.5
4.0
0
0.5
1.0
1.5
2.0
2.5
3.0
3.5
4.0
-5
0.5
1.0
1.5
2.0
2.5
3.0
3.5
4.0
FREQUENCY (GHz)
FREQUENCY (GHz)
FREQUENCY (GHz)
Figure 1. Minimum Noise Figure (Optimum Tun-
ing) vs. Frequency and Temperature.
Figure 2. Associated Gain (Optimum Tuning) vs.
Frequency and Temperature.
Figure 3. Output Power for 1 dB Gain Compres-
sion (into 50 Ω) vs. Frequency and Temperature.
0
5
20
ASSOCIATED GAIN (dB)
4
NOISE
FIGURE (dB)
15
P
1dB
(dBm)
-1
3
3.3
V
3.0
V
2.7 V
10
3.3
V
3.0
V
2.7 V
-2
3.3
V
3.0
V
2.7 V
2
-3
1
5
-4
0
0.5
1.0
1.5
2.0
2.5
3.0
3.5
4.0
0
0.5
1.0
1.5
2.0
2.5
3.0
3.5
4.0
-5
0.5
1.0
1.5
2.0
2.5
3.0
3.5
4.0
FREQUENCY (GHz)
FREQUENCY (GHz)
FREQUENCY (GHz)
Figure 4. Minimum Noise Figure (Optimum Tun-
ing) vs. Frequency and Voltage.
Figure 5. Associated Gain (Optimum Tuning) vs.
Frequency and Voltage.
Figure 6. Output Power for 1 dB Gain Compres-
sion (into 50 Ω) vs. Frequency and Voltage.
4.0
3.5
NOISE
FIGURE (dB)
5.0
4.5
4.0
3.5
Ga 50
3.0
NF
50
2.5
2.0
1.5
1.0
1.5
2.0
2.5
3.0
3.5
4.0
1.0
0.5
1.0
1.5
2.0
2.5
3.0
NF OPT
20
6
5
15
ASSOCIATED GAIN (dB)
CURRENT
(mA)
VSWR
(n:1)
3.0
INPUT
2.5
OUTPUT
2.0
1.5
1.0
0.5
4
3
2
1
0
+85
+50
+25
0
-40
10
5
3.5
0
4.0
0
1
2
3
4
5
6
7
VOLTAGE
(V)
FREQUENCY (GHz)
FREQUENCY (GHz)
Figure 7. Input and Output VSWR (into 50 Ω) vs.
Frequency.
Figure 8. 50 Ω Noise Figure and Associated Gain
vs. Frequency.
Figure 9. Device Current vs. Voltage.
3
MGA-87563 Applications Information
Introduction
The MGA-87563 low noise RF amplifier is designed to
simplify wireless RF applications in the 0.5 to 4 GHz
frequency range. The MGA-87563 is a two-stage, GaAs
Microwave Monolithic Integrated Circuit (MMIC) amplifier
that uses feedback to provide wideband gain. The output
is matched to 50Ω and the input is partially matched for
optimum noise figure.
A patented, active bias circuit makes use of current sources
to “re-use” the drain current in both stages of gain, thus
minimizing the required supply current and decreasing
sensitivity to variations in power supply voltage.
Biasing
The MGA-87563 is a voltage-biased device and operates
from a single +3 volt power supply. With a typical current
drain of only 4.5 mA, the MGA-87563 is very well suited
for use in battery powered applications. All bias regula-
tion circuitry is integrated into the MMIC, eliminating the
need for external DC components. RF performance is very
consistent for 3-volt battery supplies that may range from
2.7 to 3.3 volts, depending on battery “freshness” or state
of charge for rechargeable batteries. Operation up to +5
volts is discussed at the end of the Applications section.
The test circuit in Figure 10 illustrates a suitable method for
bringing bias into the MGA-87563. The bias connection
must be designed so that it adequately bypasses the V
dd
terminal while not inadvertently creating any resonances
at frequencies where the MGA-87563 has gain.
The 10Ω resistor, R1, serves to “de-Q” any potential
resonances in the bias line that could lead to low gain,
unwanted gain variations or device instability. The power
supply end of R1 is bypassed to ground with capacitor C1.
The suggested value for C1 is 100 pF. Significantly higher
values for C1 are not recommended. Many higher value
chip capacitors (e.g., 1000 pF) are not of sufficiently high
quality at these frequencies to function well as a RF bypass
without adding harmful parasitics or self-resonances.
While the input and output terminals are internally resis-
tively grounded, these pins should not be considered to be
current sinks. Connection of the MGA-87563 amplifier to
circuits that are at ground potential may be made without
the additional cost and PCB space needed for DC blocking
capacitors. If the amplifier is to be cascaded with active
circuits having non-zero voltages present, the use of series
blocking capacitors is recommended.
Test Circuit
The circuit shown in Figure 10 is used for 100% RF testing
of Noise Figure and Gain. The input of this circuit is fixed
tuned for a conjugate power match (maximum power
transfer, or, minimum Input VSWR) at 2 GHz. Tests in this
circuit are used to guarantee the NF
test
and G
test
parameters
shown in the Electrical Specifications table.
The 4.7 nH inductor, L1 (Coilcraft, Cary, IL part number series
1008CT-040) placed in series with the input of the amplifier
is all that is necessary to match the input to 50Ω at 2 GHz.
C1
V
dd
10
Ω
RF
INPUT
50
Ω
L1
4.7 nH
50
Ω
RF
OUTPUT
Figure 10. Test Circuit for 2 GHz.
Input Matching
The input of the MGA-87563 is partially matched internally
to 50 Ω. The use of a simple input conjugate matching
circuit (such as shown in Figure 10 for 2 GHz), will lower
the noise figure considerably. A significant advantage of
the MGA-87563’s design is that the impedance match for
NF
o
(minimum noise figure) is very close to a conjugate
power match. This means that a very low noise figure can
be realized simultaneously with a low input VSWR. The
typical difference between the noise figure obtainable
with a conjugate power match at the input and NF
o
is
only about 0.2 dB.
Phase Reference Planes
The positions of the reference planes used to measure
S-Parameters and to specify
*
opt
for the Noise Parameters
are shown in Figure 11. As seen in the illustration, the
reference planes are located at the extremities of the
package leads.
REFERENCE
PLANES
TEST CIRCUIT
Figure 11. Reference Planes.
5
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