ETC RF2431

RF2431
8
HIGH FREQUENCY LNA/MIXER
Typical Applications
• UHF Digital and Analog Receivers
• Commercial and Consumer Systems
• Digital Communication Systems
• Portable Battery-Powered Equipment
• Spread-Spectrum Communication Systems • General Purpose Frequency Conversion
Product Description
.157
.150
1
GaAs HBT
Si Bi-CMOS
SiGe HBT
ü
.010
.004
.393
.386
.050
.244
.228
8
.065
.043
8 °MAX
0°MIN
.050
.016
Optimum Technology Matching® Applied
Si BJT
.018
.014
FRONT-ENDS
The RF2431 is a monolithic integrated UHF receiver
front-end. The IC contains all of the required components
to implement the RF functions of the receiver except for
the passive filtering and LO generation. It contains an
LNA (low-noise amplifier), a second RF amplifier, a dualgate GaAs FET mixer, and an IF output buffer amplifier
which will drive a 50Ω load. Alternatively, the IF output
may be matched to a higher impedance at significantly
reduced current. The output of the LNA is made available
as an output to permit the insertion of a bandpass filter
between the LNA and the RF/Mixer section. The LNA output is buffered to permit a wide range of choices for the
interstage filter without altering the VSWR or noise figure
at the LNA input and to provide high isolation from the LO
to the input port.
.010
.007
Package Style: SOP-16
GaAs MESFET
Si CMOS
Features
• Single 3V to 6.5V Power Supply
• 1500MHz to 2500MHz Operation
LN A
16 LN A O U T
• 23dB Small Signal Gain
GND 2
15 G N D
• 3.5dB Cascaded Noise Figure
VDD1 3
14 N /C
VDD2 4
13 N /C
LN A IN 1
IF 1 5
12 D E C
IF 2 6
• 13mA DC Current Consumption
• -14dBm Input IP3
11 N /C
BUFFER
GND 7
10 G N D
RF AMP
LO IN 8
9 R F IN
M IX E R
Functional Block Diagram
Rev B1 010329
Ordering Information
RF2431
High Frequency LNA/Mixer
RF2431 PCBA-L Fully Assembled Evaluation Board (1.8GHz)
RF2431 PCBA-H Fully Assembled Evaluation Board (2.5GHz)
RF Micro Devices, Inc.
7625 Thorndike Road
Greensboro, NC 27409, USA
Tel (336) 664 1233
Fax (336) 664 0454
http://www.rfmd.com
8-43
RF2431
Absolute Maximum Ratings
Parameter
Supply Voltage
Input LO and RF Levels
Operating Ambient Temperature
Storage Temperature
Parameter (1800MHz)
Rating
Unit
-0.5 to 7.0
+6
-40 to +85
-40 to +150
VDC
dBm
°C
°C
Specification
Min.
Typ.
Max.
Caution! ESD sensitive device.
RF Micro Devices believes the furnished information is correct and accurate
at the time of this printing. However, RF Micro Devices reserves the right to
make changes to its products without notice. RF Micro Devices does not
assume responsibility for the use of the described product(s).
Unit
T = 25°C, VCC =5V, RF=1800MHz,
LO=0dBm
Overall
RF Frequency Range
IF Frequency Range
Cascade Gain
15
Cascade IP3
Cascade Noise Figure
Condition
1500 to 2500
DC to 400
23
19
-14
3.5
MHz
MHz
dB
dB
dBm
dB
2.6
2.5:1
+2
13
30
1.5:1
dB
IF=100MHz, 50Ω load
IF=350MHz, 50Ω load
Referenced to the input
Single sideband
First Section (LNA)
FRONT-ENDS
8
Noise Figure
Input VSWR
Input IP3
Gain
Reverse Isolation
Output VSWR
No external matching
dBm
dB
dB
No external matching
High impedance output, 1.3kΩ load
Second Section (RF Amp,
Mixer, IF1)
Noise Figure
Input VSWR
Input IP3
Conversion Gain
Output Impedance
9.5
1.7:1
-1
6
4
dB
dBm
dB
kΩ
Second Section (RF Amp,
Mixer, IF2)
Noise Figure
Input VSWR
Input IP3
Conversion Gain
Output VSWR
9.5
1.7:1
-1
6
1.2:1
dB
Single sideband
Open drain
Buffered output, 50Ω load
Single sideband
dBm
dB
LO Input
LO Level
LO to RF Rejection
LO to IF Rejection
LO Input VSWR
-6 to +6
15
25
1.5:1
dBm
dB
dB
Power Supply
Voltage
Current Consumption
8-44
3 to 6.5
19
13
25
V
mA
mA
VDD =5.0V, LNA On, Mixer On, Buffer On
VDD =5.0V, LNA On, Mixer On, Buffer Off
Rev B1 010329
RF2431
Parameter (2400MHz)
Specification
Min.
Typ.
Max.
Unit
T = 25°C, VCC =5V, RF=2400MHz,
LO=0dBm
Overall
RF Frequency Range
IF Frequency Range
Cascade Gain
Cascade IP3
Cascade Noise Figure
Condition
2.0 to 2.5
DC to 400
13
10
-11
4.5
GHz
MHz
dB
dB
dBm
dB
2.9
1.8:1
0
10
25
1.6:1
dB
IF=100MHz, 50Ω load
IF=350MHz, 50Ω load
Referenced to the input
Single sideband
First Section (LNA)
No external matching
dBm
dB
dB
No external matching
High impedance output, 1.3kΩ load
Second Section (RF Amp,
Mixer, IF1)
Noise Figure
Input VSWR
Input IP3
Conversion Gain
Output Impedance
10
1.5:1
-1
3
4
dB
dBm
dB
kΩ
Second Section (RF Amp,
Mixer, IF2)
Noise Figure
Input VSWR
Input IP3
Conversion Gain
Output VSWR
10
1.5:1
-1
3
1.2:1
dB
Single sideband
Open drain
Buffered output, 50Ω load
8
Single sideband
FRONT-ENDS
Noise Figure
Input VSWR
Input IP3
Gain
Reverse Isolation
Output VSWR
dBm
dB
LO Input
LO Level
LO to RF Rejection
LO to IF Rejection
LO Input VSWR
-6 to +6
15
20
1.4:1
dBm
dB
dB
3 to 6.5
19
13
V
mA
mA
Power Supply
Voltage
Current Consumption
Rev B1 010329
VDD =5.0V, LNA On, Mixer On, Buffer On
VDD =5.0V, LNA On, Mixer On, Buffer Off
8-45
RF2431
Pin
1
FRONT-ENDS
8
Function
LNA IN
2
GND
3
VDD1
4
VDD2
5
IF1 OUT
6
7
8
IF2 OUT
GND
LO IN
9
RF IN+
10
11
12
GND
NC
RF BYP
13
14
15
NC
NC
GND
8-46
Description
This pin is NOT internally DC blocked. An external blocking capacitor
must be provided if the pin is connected to a device with DC present. A
DC path to ground (i.e. an inductor or resistor to ground) is, however,
acceptable at this pin. If a blocking capacitor is required, a value of
22pF is recommended.
Interface Schematic
LNA IN
Ground connection. Keep traces physically short and connect immediately to ground plane for best performance.
Supply voltage for the LNA only. A 22pF external bypass capacitor is
required and an additional 0.01µF is required if no other low frequency
bypass capacitors are nearby. The trace length between the pin and the
bypass capacitors should be minimized. The ground side of the bypass
capacitors should connect immediately to ground plane.
Power supply for the IF buffer amplifier. If the high impedance mixer
output is being used, then this pin is not connected.
Open drain output port, one of the two output options. This pin must be
connected to VDD through a resistor in order to bias the mixer, even
when using the IF2 Output. In addition, a 0.1µF bypass capacitor is
required at the other end of the bias resistor. This output is intended to
drive high impedance IF filters. The intrinsic output impedance is about
4kΩ, which means that the actual impedance is set by the external
resistor to VDD.
IF1 OUT
50Ω buffered output port, one of the two output options. This is an
open drain output, therefore a resistor to ground is needed. The typical
value for this resistor is 470Ω. Pin 4 must be connected to VDD in order
to turn the buffer amplifier on. Current drain will increase by approximately 6mA at 5V; by approximately 3mA at 3V.This pin is not connected when using the high impedance port.
Same as pin 2.
Mixer LO input. An high-pass matching network, such as a single shunt
inductor (as shown in the application schematics), is the recommended
topology because it also rejects IF noise at the mixer input. The value
of this inductor is depending on the frequency, see the application
schematics. This filtering is required to achieve the specified noise figures. This pin is NOT internally DC blocked. An external blocking
capacitor must be provided if the pin is connected to a device with DC
present. A DC path to ground (i.e. an inductor or resistor to ground) is,
however, acceptable at this pin. If a blocking capacitor is required, a
value of 22pF is recommended.
Mixer RF Input port. This pin is NOT internally DC blocked. An external
blocking capacitor must be provided if the pin is connected to a device
with DC present. A DC path to ground (i.e. an inductor or resistor to
ground) is, however, acceptable at this pin. If a blocking capacitor is
required, a value of 22pF is recommended. Matching is required; see
the applications schematics.To minimize the noise figure it is recommended to have a bandpass filter before this input. This will prevent the
noise at the image frequency from being converted to the IF.
Same as pin 2.
IF2 OUT
LO IN
RF IN
No connection
Connection for the external bypass capacitor for the mixer input buffer
amplifier. 1nF is recommended. The trace length between the pin and
the capacitor should be minimized. The ground side of the bypass
capacitor should connect immediately to ground plane.
No connection.
No connection.
Same as pin 2.
Rev B1 010329
RF2431
Pin
16
Function
LNA OUT
Description
Interface Schematic
50Ω output. Internally DC blocked.
LNA OUT
FRONT-ENDS
8
Rev B1 010329
8-47
RF2431
Application Schematic
1800MHz, High Impedance Output
LN A
R F IN
VD
1
16
2
15
3
14
4
13
5
12
6
11
D
1 00 n F
22 p F
< 1 kΩ
5 0 Ω Im a ge F ilter
1 nF
IF O U T
BUFFER
1 nF
10
7
M IX E R
LO IN
RF AMP
3 .3 n H
9
8
4.7 nH
8
1 .8 p F
FRONT-ENDS
Application Schematic
2400MHz, High Impedance Output
LN A
R F IN
VD
1
16
2
15
3
14
4
13
5
12
6
11
D
1 00 n F
22 p F
< 1 kΩ
5 0 Ω Im a ge F ilter
1 nF
IF O U T
BUFFER
1 nF
10
7
M IX E R
LO IN
8
1.8 nH
8-48
1 .8 n H
RF AMP
9
0 .9 p F
Rev B1 010329
RF2431
Application Schematic
1800MHz, Buffered Output
LN A
R F IN
VDD
10 0 nF
1
16
2
15
3
14
4
13
5
12
6
11
22 p F
< 1 kΩ
5 0 Ω Im a ge F ilter
1 nF
1 nF
IF O U T
4 70 Ω
BUFFER
10
7
M IX E R
LO IN
RF AMP
3.3 nH
9
8
4 .7 nH
1 .8 p F
8
FRONT-ENDS
Application Schematic
2400MHz, Buffered Output
LN A
R F IN
VDD
10 0 nF
1
16
2
15
3
14
4
13
5
12
6
11
22 p F
< 1 kΩ
5 0 Ω Im a ge F ilter
1 nF
1 nF
IF O U T
4 70 Ω
BUFFER
10
7
M IX E R
LO IN
8
1 .8 nH
Rev B1 010329
RF AMP
1.8 nH
9
0 .9 p F
8-49
RF2431
Evaluation Board Schematic
2400MHz
(Download Bill of Materials from www.rfmd.com.)
P1
P 1 -1
P 1 -3
C1
4 7 pF
C2
10 0 nF
L O IN
J4
C4
1 nF
R2
80 0 Ω
R1
47 0 Ω
FRONT-ENDS
GND
2 43 14 00 R ev D
T un ed for 2 .4 G H z
LO M atch @ 2 .4 G H z
3
5 0 Ω µstrip
1
16
2
15
3
14
4
13
5
12
6
11
LN A O U T
J2
C3
1 nF
BUFFER
10
7
50 Ω µstrip
M IX E R
8
L1
4 .7 n H
8-50
2
LNA
P 1-1
8
VCC
5 0 Ω µstrip
L N A IN
J1
IF O U T
J5
1
RF AMP
L2
1 .8 nH
50 Ω µstrip
9
R F IN
J3
C5
0.9 pF
Rev B1 010329
RF2431
Evaluation Board Schematic
1800MHz
P1
P 1 -1
P 1 -3
2
GND
C1
4 7 pF
C2
10 0 nF
C4
1 nF
2 43 14 01 R ev D
T un ed for 1 .8 G H z
LO M atch @ 1 .8 G H z
3
5 0 Ω µstrip
LNA
P 1-1
L O IN
J4
VCC
5 0 Ω µstrip
L N A IN
J1
IF O U T
J5
1
R2
80 0 Ω
R1
47 0 Ω
1
16
2
15
3
14
4
13
5
12
6
11
C3
1 nF
BUFFER
10
7
5 0 Ω µstrip
M IX E R
8
RF AMP
L2
3 .3 nH
50 Ω µstrip
9
8
R F IN
J3
C5
1.8 pF
FRONT-ENDS
L1
4 .7 n H
LN A O U T
J2
Rev B1 010329
8-51
RF2431
Evaluation Board Layout
2400MHz
Evaluation Board Layout
1800MHz
FRONT-ENDS
8
8-52
Rev B1 010329