INA-12063-TR1 Agilent(Hewlett-Packard), INA-12063-TR1 Datasheet - Page 16

• Manufacturer Part Number: INA-12063-TR1
• Description: 1.5 GHz Low Noise Self-Biased Transistor Amplifier
• Manufacturer: Agilent(Hewlett-Packard)

Figure 17. Input Impedance Match.
As shown in Figure 17, a shunt
capacitor of 0.59 pF will move
the unit conductance circle (G=1)
at Point B. A 11.2 nH series
inductor then completes the
match to 50
impedance at Point B to the
center of the chart.
The value of the shunt capacitor
is small enough that a short
length of open-circuit transmis-
sion line could be used in place of
the lumped element capacitor.
This saves the expense of a chip
component with the tradeoff of a
small amount of additional circuit
board space. A 0.20-inch length of
open-circuit 50
choice that would be equivalent
to the 0.59 pF shunt capacitor.
The input matching circuit is
shown in Figure 19.
Results of this step:
The input circuit is:
Figure 18. Input Circuit.
-0.2
0.2
opt
INPUT
RF
* at Point A to a position on
0.2
-0.5
0.5
11.2 nH
Input
C (50 ) B
RF
0.5
0.59 pF
L1
by moving the
C
1
line is one
C1
-1
1
A (
opt
*)
2
B
A
-2
2
7. Design of the output
impedance matching network.
Using the circuit file from step 4
(Figure 15), Touchstone was used
to calculate the load impedance
to achieve maximum power
transfer. The conjugate of
Point A on the Smith chart in
Figure 19.
Figure 19. Output Impedance Match.
The two possible L-C networks
that can be used to match
50
or a shunt L-series C circuit. By
choosing the shunt L-series C
circuit, two of the DC consider-
ations from Step 5 can be satis-
fied: the shunt L can be bypassed
and used to apply the +3 volt
supply to the RF output terminal,
and the series C will serve double
duty as the DC blocking capacitor.
Referring again to Figure 19, a
shunt inductance of 10.8 nH
moves
which is on the G1 circle of the
Smith chart. The addition of
1.9 pF of series capacitance
completes the impedance trans-
formation to Point C at the center
of the chart. The output matching
circuit is shown in Figure 20.
-0.2
0.2
ml
ml
* (0.62 -35 ), is plotted as
(0.62 +35 ) of the INA-12063
0.2
are either a shunt C-series L
-0.5
A (
0.5
ml
ml
L2
*)
* at Point A to Point B
0.5
B
C2
6-131
C (50 )
C
1
Output
-1
1
RF
2
B
A
ml
ml
-2
* to
,
2
Results of this step:
The output circuit is:
Figure 20. Output Circuit.
The circuit values from this step
and from Step 6 will be used as a
starting point to be refined in
Step 9 when the circuit is ex-
panded to take practical intercon-
nections and parasitics into
account.
8. PCB Layout. The results of
the preceding steps and the PCB
layout guidelines in design Step 8
were used to draft the circuit
board layout shown in Figure 21.
Since parasitic effects are mini-
mal, the current source resistor,
R2, can be conveniently placed
directly from the RF output to the
I
tor is added to the shunt stabiliz-
ing resistor, R1 and matching
inductor, L2, on the output. A DC
blocking capacitor, C1, is in-
cluded at the input to complete
the amplifier.
Figure 21. PCB Layout of 900 MHz
LNA.
Results of this step:
PCB layout completed.
bias
connection. A bypass capaci-
11.2 nH
0.59 pF
OUTPUT
RF