AMMC-5023 Datasheet, PDF (7/9 Pages) Agilent(Hewlett-Packard) – 23 GHz Low Noise Amplifier (21.2-26.5 GHz)

Biasing and Operation
The AMMC-5023 has four
cascaded gain stages as shown in
Figure 19. The first two gain
stages at the input are biased with
the V_D1 drain supply. Similarly,
the two output stages are biased
with the V_D2 supply. Standard
LNA operation is with a single
positive DC drain supply voltage
(V_D1=V_D2= 5 V) as shown in the
assembly diagram, Figure 2(a).
If desired, the output stage DC
supply voltage (V_D2) can be
increased to improve output
power capability while maintain-
ing optimum low noise bias
conditions for the input section.
The output power may also be
adjusted by applying a positive
voltage at V_G2 to alter the operat-
ing bias point for both the output
FETs. Increasing the voltage
applied to V_G2 (more positively)
results in a more negative gate-
to-source voltage and, therefore,
lower drain current. Figures
20(b) and 20(c) illustrate how the
device can be assembled for
independent drain supply
operation and for output stage
gate bias control.
Assembly Techniques
The chip should be attached
directly to the ground plane
using either a fluxless AuSn
solder preform or electrically
conductive epoxy^[1]. For conduc-
tive epoxy, the amount should be
just enough to provide a thin
fillet around the bottom perim-
eter of the die. The ground plane
should be free of any residue that
may jeopardize electrical or
mechanical attachment. Caution
should be taken to not exceed the
Absolute Maximum Rating for
assembly temperature and time.
Thermosonic wedge bonding is
the preferred method for wire
attachment to the bond pads. The
RF connections should be kept as
short as possible to minimize
inductance. Gold mesh^[2] or
double-bonding with 0.7 mil gold
wire is recommended.
Mesh can be attached using a
2 mil round tracking tool and a
tool force of approximately
22 grams with an ultrasonic
power of roughly 55 dB for a
duration of 76 ± 8 mS. A guided
wedge at an ultrasonic power
level of 64 dB can be used for the
0.7 mil wire. The recommended
wire bond stage temperature is
150 ± 2° C.
The chip is 100 mm thick and
should be handled with care.
This MMIC has exposed air
bridges on the top surface.
Handle at edges or with a custom
collet (do not pick up die with
vacuum on die center.)
This MMIC is also static sensitive
and ESD handling precautions
should be taken.
For more information, see
Agilent Application Note 54
“GaAs MMIC ESD, Die Attach
and Bonding Guidelines.”
Notes:
1. Ablebond 84-1 LM1 silver
epoxy is recommended.
2. Buckbee-Mears Corporation,
St. Paul, MN, 800-262-3824.
RF Input
RF Output
V_G1
V_D1
V_G2
V_D2
Figure 19. AMMC-5023 Schematic.
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