INA-12063-TR1 Agilent(Hewlett-Packard), INA-12063-TR1 Datasheet - Page 12

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

Case 2 (K>1 within the band of
interest; K<1 for some frequen-
cies outside of the band of
interest ) is the next simplest case
to handle. Since K>1 in the band
of interest, little or no perfor-
mance tradeoffs may be needed
to make the amplifier uncondi-
tionally stable.
By using R-C or R-L combina-
tions, frequency selective resis-
tive loading can be applied only
over the frequency range for
which K < 1 in order to stabilize
the amplifier without adversely
affecting in-band performance.
Case 3 (K<1 in the band of inter-
est) requires tradeoffs in NF or
output power to achieve an uncon-
ditionally stable amplifier stage.
The INA-12063 typically falls into
either Case 2 or Case 3, depending
on the bias current, circuit ground-
ing, and frequency band of interest.
In all cases, a final check of
stability should be done in the
analysis of the completed ampli-
fier design. This is done as part of
Step 9 in the design sequence.
Step 5. DC Connections
The DC connections to the
INA-12063 are considerations in
the next two steps in which the
input and output impedance
matching networks are chosen.
The goal is economy of compo-
nents by integrating as many of
the DC connections into the
matching circuits as practical.
For example the use of a series C
in an impedance matching
network could double as a DC
blocking capacitor. Or, a shunt L
can be used to apply the required
supply voltage to the output of
the INA-12063.
One of the advantages of the
active bias circuit in the
INA-12063 is that there is no need
for an external DC bias connec-
tion to the RF Input. If desired,
the input may be connected
directly to matching networks
using a series capacitor as the
first element.
Pins 4 and 6 are connected to the
supply voltage and Pins 2 and 5
are DC grounded. Pins 1 and 4
should be bypassed to ground. A
high value resistor from Pin 1 to
Pin 6 is a simple and convenient
method for setting the device
operating current. Pin 3, has an
internal voltage present and is
normally connected to a DC
blocking capacitor. The only DC
connection which could affect RF
performance is that of applying
the supply voltage to the RF
Output pin.
Step 6. Designing the Input
Match
The input impedance match is
generally designed to achieve
either of two goals, either lowest
noise figure or maximum power
transfer. The maximum power
transfer match provides maxi-
mum gain and corresponds to
minimum VSWR. In some cases,
noise circles in combination with
constant gain circles are used to
design an intermediate match
point to achieve a compromise in
performance between low noise
figure and low input VSWR.
If the design goal is to obtain
lowest NF, the input of the
INA-12063 is matched to the
conjugate of
reflection coefficient of the
source termination that results in
F
noise figure.
found in the tables of Typical
Noise Parameters. Alternatively
min
, the lowest possible device
opt
opt
6-127
.
design data are
opt
is the
same CAD circuit file used in the
stability analysis in Step 4 above.
This method is slightly more
accurate since it takes the
feedback effects of device
grounding and stabilization
components into account.
If the design goal is to obtain
maximum power transfer (maxi-
mum gain/minimum input VSWR),
then the input of the INA-12063 is
matched to
impedance resulting from the
simultaneous conjugate match of
the input and output of the
device. Since
for devices/circuits with K > 1,
the CAD circuit file from design
Step 4, including any stabilizing
resistors, is used to calculate
For most communication systems
operating over relatively small
bandwidths, a single frequency
match approach is usually
adequate. As a general rule, the
selection of high pass networks
for the input (and output) match-
ing circuits is desirable to reduce
excess gain at low frequencies.
As a final note in the choice of the
input matching structure, the use
of a series C element is possible
at the input of the INA-12063
since the internal bias circuit
obviates the need for an external
DC connection to the input.
The choice of using either lumped
element or distributed (transmis-
sion line) matching elements is
mainly dictated by size and
frequency constraints as well as
by cost considerations. While
distributed elements are “free”
since they are etched onto the
PCB, they usually use more board
space than an equivalent lumped
element (chip) component.
opt
can be calculated using the
ms
ms
.
ms
is only defined
is the source
ms
.