HMMC-5040 Applications
The HMMC-5040 broadband
amplifier is designed for both
military (35 GHz) applications
and wireless communication
systems that operate at 23, 28,
and 38 GHz. It is also suitable for
use as a frequency multiplier due
to excellent below-band input
return loss and high gain.
No ground wires are needed since
ground connections are made
with plated through-holes to the
backside of the device.
The HMMC-5040 can also be used
to double, triple, or quadruple the
frequency of input signals. Many
bias schemes may be used to
generate and amplify desired
harmonics within the device. The
information given here is
intended to be used by the
customer as a starting point for
such applications. Optimum
conversion efficiency is obtained
with approximately 14 dBm input
drive level.
As a doubler, the device can
multiply an input signal in the
10-20 GHz frequency range up to
20-40 GHz with conversion gain
for output frequencies exceeding
30 GHz. Similarly, 5-10 GHz
signals can be quadrupled to
20-40 GHz with some conversion
loss. Frequency doubling or
quadrupling is accomplished by
operating the first gain stage at
pinch-off (V
G1
= V
P
≅
-1.2 volts).
Stages 2, 3, and 4 are biased for
normal amplification. The assem-
bly diagram shown in Figure 12b
can be used.
To operate the device as a
frequency
tripler
the drain
voltage can be reduced to
approximately 2.5 volts and the
gate voltage can be set at about
-0.4 volts or adjusted to minimize
second harmonics if needed.
Either of Figures 12a or Figure
12b can be used.
Contact your local HP sales
representative for additional
information concerning multiplier
performance and operating
conditions.
Assembly Techniques
Solder die attach using a fluxless
gold-tin (AuSn) solder preform is
the recommended assembly
method. A conductive epoxy such
as ABLEBOND
®
71-1LM1 or
ABLEBOND
®
36-2 may also be
used for die attaching provided
the Absolute Maximum Ratings
are not exceeded. The device
should be attached to an electri-
cally conductive surface to
complete the DC and RF ground
paths. The backside metallization
on the device is gold.
It is recommended that the RF
input and output connections be
made using either 500 lines/inch
(or equivalent) gold wire mesh.
The RF connections should be
kept as short as possible to
minimize inductance. The DC
bias supply wires can be 0.7 mil
diameter gold.
Thermosonic wedge is the
preferred method for wire
bonding to the gold bond pads.
Mesh wires can be attached using
a 2 mil round tacking tool and a
tool force of approximately
22 grams with an ultrasonic
power of roughly 55 dB for a
duration of 76
±
8 msec. 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.
For more detailed information
see HP application note #999
“GaAs MMIC Assembly and
Handling Guidelines.”
GaAs MMICs are ESD sensitive.
Proper precautions should be used
when handling these devices.
Biasing and Operation
The recommended DC bias
condition is with all drains
connected to single 4.5 volt (or
less) supply and all gates con-
nected to an adjustable negative
voltage supply as shown in Figure
12a. The gate voltage is adjusted
for a total drain supply current of
typically up to 300 mA. Figures 4,
5, 8, and 9 can be used to help
estimate the minimum drain
voltage and current necessary for
a given RF gain and output
power.
The second, third, and fourth
stage DC drain bias lines are
connected internally (Figure 1)
and therefore require only a
single bond wire. An additional
bond wire is needed for the first
stage DC drain bias, V
D1
.
Only the third and fourth stage
DC gate bias lines are connected
internally. A total of three DC
gate bond wires are required: one
for V
G1
, one for V
G2
, and one for
the V
G3
-to-V
G4
connection.
The RF input has matching
circuitry that creates a 50 ohm
DC and RF path to ground. A DC
blocking capacitor should be
used in the RF input transmission
line. Any DC voltage applied to
the RF input must be maintained
below 1 volt. The RF output is
AC-coupled.
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