INA-12063-TR1 Agilent(Hewlett-Packard), INA-12063-TR1 Datasheet - Page 8

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

1
INA-12063 Applications
Information
Introduction
The INA-12063 is a unique RFIC
configuration that combines the
performance flexibility of a
discrete transistor with the
simplicity of using an integrated
circuit.
The INA-12063 is an integrated
circuit that combines three
functions: (1) a silicon bipolar RF
transistor, (2) an RF feedback
network, and (3) a patented
bias regulation circuit. A simpli-
fied schematic diagram of the
INA-12063 is shown in Figure 9.
The result is a versatile gain stage
that can be operated from a single
+1.5 to +5 volt power supply with
the device current set by the user.
The INA-12063 is designed for use
in battery powered equipment
demanding high performance
with low supply voltages and
minimal current drain. Typical
applications for the INA-12063
include low noise RF amplifiers,
IF amplifiers, gain and buffer
stages through 2 GHz. The
INA-12063 is an excellent choice
for use in cellular and cordless
telephones, PCS, W/LAN’s, RF
modems and other commercial
wireless equipment.
GND 2
Figure 9. INA-12063 Schematic.
INPUT
U.S. Patent Number 5436595
RF
CIRCUIT
ACTIVE
BIAS
GND 1
TRANSISTOR
V
FEEDBACK
NETWORK
d
RF
RF
[1]
RF
OUTPUT
and V
I
bias
c
Description
The active bias circuit solves
three problems normally encoun-
tered with traditional approaches
for biasing discrete transistors.
First, as an active bias circuit, the
emitter of the RF transistor is DC
grounded. This permits the
collector current to be controlled
without the need for resistors
and/or bypass capacitors in the
emitter that may degrade RF
performance.
Second, the internal bias circuit
greatly simplifies the design tasks
commonly associated with bias-
ing transistors, such as accurately
regulating the collector current,
allowing for variations in h
making a non-intrusive DC
connection to the base of the
transistor, and stabilizing current
over temperature.
And, third, the integrated bias
circuit eliminates the cost, parts
count, and associated PCB space
required for as many as 8 addi-
tional DC components.
The integrated bias control circuit
is very easy to use. For most
applications, the collector current
for the RF transistor can be set
with a single resistor.
The geometry of the integrated
RF transistor is designed to
provide an excellent balance
between low noise figure, high
gain, and good dynamic range
while retaining practical imped-
ance matching levels. The operat-
ing current is typically in the 1 to
10 mA range.
The integrated RF feedback
contains an inductive element in
the emitter circuit of the RF
transistor. This series feedback
6-123
FE
,
configuration is of the type often
implemented in discrete transis-
tor designs for the purpose of
improving stability and bringing
the optimum noise match at the
input of the transistor closer to
50
applications, a simple, series
inductor is often all that is needed
to adequately match the input of
the INA-12063 to 50 .
In contrast to amplifiers that use
resistive feedback to achieve
broadband 50
matches, the INA-12063 leaves
the designer with the flexibility of
optimizing performance for a
particular frequency band. For
example, frequency selective
input and output impedance
matching circuits can be used to
tune for optimum NF, maximum
output power, low input VSWR,
or to tailor the passband response
to eliminate undesirable gain
responses.
Setting the Bias Current
The integrated, active bias circuit
is a 10:1 current mirror. The
current mirror forces the collec-
tor current in the RF transistor to
be approximately 10 times the
current supplied to the I
In normal use, a voltage between
+1.5 and +5 volts, is applied to
both the V
the INA-12063. Although normally
connected to the same supply
voltage, it is not necessary that
both V
voltage.
The collector current of the RF
transistor is then set by injecting
a small control current into the
I
1/10 of the desired collector
current.
bias
pin that is approximately
. The result is that for many
d
and V
d
and V
c
be at the same
input and output
c
terminals of
bias
pin.