INA-12063-BLK HP [Agilent(Hewlett-Packard)], INA-12063-BLK Datasheet - Page 9

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

While there are any number of
means of supplying the I
control current, the simplest way
is to merely place a resistor
between the V
nals, shown as “R
Figure 10. R
ciently high to act as a current
source. The value for R
calculated as follows:
where V
is the desired collector current,
and R
determining resistor. For ex-
ample, for a desired collector
current of 1.5 mA and a power
supply of 2.7 volts, the value of
R
Power Down
A power-down function for the
INA-12063 can be conveniently
implemented by switching the
I
advantage of switching only a
very small current since I
typically only a fraction of a mA.
INPUT
Figure 10. Single-Resistor Bias
Circuit.
Amplifier Application
Guidelines
This section describes the general
approach for designing amplifiers
using the INA-12063. This is a
generic design approach and is
applicable for most low noise RF
or IF amplifiers or for general
purpose gain and buffer stages.
bias
RF
bias
GND 2
R
current. This method has the
would be 12.7 K .
bias
bias
d
CIRCUIT
V
ACTIVE
= 10
is the value of the bias
is the device voltage, I
BIAS
d
GND 1
FEEDBACK
bias
CIRCUIT
d
(
RF
and I
TRANSISTOR
will be suffi-
V
bias
RF
d
I
– 0.8
” in
c
bias
I
V
bias
c
bias
I
c
bias
termi-
R
bias
)
bias
ISOLATION
is
BIAS
RF OUTPUT
is
VOLTAGE
SUPPLY
(1)
c
The following “10-step” program
is suggested as the design se-
quence:
1. Determine performance goals.
2. Select the bias condition.
3. Choose PCB material.
4. Check stability.
5. Determine required DC
6. Design the input impedance
7. Design the output impedance
8. Layout the printed circuit
9. Computer optimization and
10. Fabricate, assemble, and test.
Each of these steps in the design
sequence will now be discussed
in the following sections.
Step 1. Establish Performance
Goals
The first step in the design of an
INA-12063 amplifier stage is to
establish performance goals. It
may be necessary to consider
performance tradeoffs between
some amplifier parameters, such
as Noise Figure, Input VSWR,
Gain, Output Power, Output
VSWR, Stability, and DC power
consumption.
Some of these parameters are
counterposed, for example,
increased output power requires
greater DC power consumption.
The tradeoff decisions may
require consideration of the
choice of DC bias which is
discussed in the next section. The
final design will often be a
balance between system-critical
performance and those param-
eters of lesser significance.
connections.
matching network.
matching network.
board.
performance verification.
6-124
Step 2. Choose Bias
Conditions
The second step of the design
process is to choose the bias
conditions, i.e., the RF transistor
operating voltage (V
current (I
are chosen at this step in the
design sequence since many of
the RF design characteristics
(e.g., S-parameters and noise
parameters) are dependent on
current and/or voltage.
The choice of bias voltage is often
preemptive as it is normally fixed
by available system resources,
such as a battery voltage or
system power supply. The
INA-12063 will operate from
supply voltages from 1.5 to
5 volts, with +3 volts considered
to be the typical operating
voltage.
Although noise figure and gain
are somewhat insensitive to
device voltage as an independent
variable, some increase in output
power can be realized with higher
device voltages.
The bias current has the greatest
effect on RF performance and the
following tradeoffs should be
considered:
Noise Figure increases with
device current. The data in the
Typical Noise Parameter tables
shows an increase in F
1.4 dB at 1.5 mA of bias current to
2.0 dB at 8 mA.
Gain – Transducer gain, |S
increases significantly in propor-
tion to device current.
Output Power – One of the
benefits of increased device
current is greater output power. A
typical increase in current from
1.5 to 8 mA results in a corre-
c
). The bias conditions
c
) and
min
21
of from
|
2
,