BF P740 E SD
Low N oise A mpli fier for Wirel e s s
LA N 2 .4 G Hz Applic ation
Applic atio n N ote A N 295
Revision: Rev. 1.0
2012-11-30
RF and P r otecti on D evic es
Edition 2012-11-30
Published by
Infineon Technologies AG
81726 Munich, Germany
© 2013 Infineon Technologies AG
All Rights Reserved.
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BFP740ESD
Low Noise Amplifier for Wireless LAN 2.4GHz Application
Application Note AN295
Revision History: 2012-11-30
Previous Revision: None
Page
Subjects (major changes since last revision)
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Last Trademarks Update 2011-11-11
Application Note AN295, Rev. 1.0
3 / 17
2012-11-30
BFP740ESD
Low Noise Amplifier for Wireless LAN 2.4GHz Application
List of Content, Figures and Tables
Table of Content
1
Introduction ........................................................................................................................................ 5
2
Application Circuit ............................................................................................................................. 6
3
Typical Measurement Results ........................................................................................................... 8
4
Measured Graphs ............................................................................................................................... 9
5
Other Miscellaneous Measurements .............................................................................................. 14
6
Evaluation Board .............................................................................................................................. 15
7
Author ................................................................................................................................................ 16
List of Figures
Figure 1
Figure 2
Figure 3
Figure 4
Figure 5
Figure 6
Figure 7
Figure 8
Figure 9
Figure 10
Figure 11
Figure 12
Figure 13
Figure 14
Figure 15
Figure 16
Block diagram....................................................................................................................................... 5
BFP740ESD Application Circuit ........................................................................................................... 6
Narrowband Isertion gain of BFP740ESD for WLAN 2.4GHz Application ........................................... 9
Wideband power gain of BFP740ESD for WLAN 2.4GHz Application ................................................ 9
Input Matching of BFP740ESD for WLAN 2.4GHz Application ......................................................... 10
Output Matching of BFP740ESD for WLAN 2.4GHz Application ....................................................... 10
Reverse Isolation of BFP740ESD for WLAN 2.4GHz Application ..................................................... 11
Noise Figure of BFP740ESD for WLAN 2.4GHz Application ............................................................. 11
Input 1 dB compression point of BFP740ESD for WLAN 2.4GHz Application .................................. 12
Output Third Order Interpoint (OIP3) of BFP740ESD for WLAN 2.4GHz Application ....................... 12
Input matching of BFP740ESD for WLAN 2.4GHz Application in the Smith Chart ........................... 13
Output matching of BFP740ESD for WLAN 2.4GHz Application in the Smith Chart ......................... 13
Stability factor k of BFP740ESD circuit for up to 10GHz ................................................................... 14
Stability factor µ1 and µ2 of BFP740ESD circuit for up to 10GHz ..................................................... 14
Populated PCB picture of BFP740ESD for WLAN 2.4GHz board (Emitter Degeneration Length
0.4mm) ............................................................................................................................................... 15
PCB layer stack .................................................................................................................................. 15
List of Tables
Table 1
Table 2
Table 3
Bill-of-Materials..................................................................................................................................... 6
Package drawing for SOT343 package ............................................................................................... 7
Electrical Characteristics (at room temperature) .................................................................................. 8
Application Note AN295, Rev. 1.0
4 / 17
2012-11-30
BFP740ESD
Low Noise Amplifier for Wireless LAN 2.4GHz Application
Introduction
1
Introduction
The BFP740ESD is a SiGe:C transistor manufacturered in the highly reliable SiGe:C technology. It offers 2kV
Human Body Model ESD robustness due to the integrated protection circuit, and is capable of working under up
to 21dBm RF input power. It offers a low noise figure (minimum value 0.65dB@2.4GHz) and high gain (25.5dB
typ.@2.4GHz) for up to 6GHz.
In the 2.4GHz ISM frequency band, the international Wireless LAN standards 802.11 b/g/n is among the major
applications. When BFP740ESD is used as low noise amplifier for the 2.4GHz Wireless LAN application, it
offers a noise figure of 0.74dB only, and provides a high gain of 18.9dB.
Rx
Diplexer
DPDT
Balun
WLAN
Transceiver
& Baseband
BFP740ESD
Antenna
diversity
Tx
Diplexer
Figure 1
LNA
PA
Balun
Block diagram
Application Note AN295, Rev. 1.0
5 / 17
2012-11-30
BFP740ESD
Low Noise Amplifier for Wireless LAN 2.4GHz Application
Application Circuit
2
Application Circuit
2.1
Schematic Diagram
Vcc= 3.0 V
J3
DC Connector
All passives are “0402“ case size
Inductors: LQG Series
Capacitors: various
I = 11.3 mA
R1
120
Ohms
R2
22k
Ohms
C3
39pF
L1
2.2nH
R3
24
Ohms
C4
39pF
L2
2.2nH
Q1: BFP740ESD
J1
RF Port1
INPUT
C2
C1
J2
RF Port2
OUTPUT
22pF
8.2pF
Figure 2
Table 1
Emitter Degeneration Micro Stripline, 0.4mm length
Total Component Count = 9
PCB = M100511 V1.40e
PCB Board Material = Standard FR4
Layer spacing (top RF to internal ground plane): 0.2 mm
Inductors = 2 (LQG Low-Q series)
Resistors = 3
Capacitors = 4
BFP740ESD Application Circuit
Bill-of-Materials
Symbol
Value
Unit
Package
Manufacturer
Comment
C1
8.2
pF
0402
Various
Input matching
C2
22
pF
0402
Various
Output matching
C3
39
pF
0402
Various
RF decoupling / blocking capacitor
C4
39
pF
0402
Various
RF decoupling / blocking capacitor
R1
120
Ω
0402
Various
DC biasing
R2
22
kΩ
0402
Various
DC biasing
R3
24
Ω
0402
Various
DC biasing
L1
2.2
nH
0402
Murata LQG15A
Input matching
L2
2.2
nH
0402
Murata LQG15A
Output matching
Q1
BFP740ESD
SOT343
Infineon
Transistor LNA in SOT343 package
Application Note AN295, Rev. 1.0
6 / 17
2012-11-30
BFP740ESD
Low Noise Amplifier for Wireless LAN 2.4GHz Application
Application Circuit
Table 2
Package drawing for SOT343 package
Application Note AN295, Rev. 1.0
7 / 17
2012-11-30
BFP740ESD
Low Noise Amplifier for Wireless LAN 2.4GHz Application
Typical Measurement Results
3
Typical Measurement Results
Table 3 shows typical measurement results of the application circuit shown in Figure 2. The values given in
these tables include losses of the board and the SMA connectors if not otherwise stated.
Table 3
Electrical Characteristics (at room temperature)
Parameter
Symbol
Value
Unit
Frequency Range
Freq
2440
MHz
DC Voltage
Vcc
3.0
V
DC Current
Icc
11.3
mA
Gain
G
18.9
dB
Noise Figure
NF
0.74
dB
Input Return Loss
RLin
10.4
dB
Output Return Loss
RLout
11.0
dB
Reverse Isolation
IRev
26.2
dB
Input P1dB
IP1dB
-12.9
dBm
Output P1dB
OP1dB
5.0
dBm
Input IP3
IIP3
-4.9
dBm
Ouput IP3
OIP3
+ 14.0
dBm
Stability
K
>1
--
Application Note AN295, Rev. 1.0
8 / 17
Comment/Test Condition
PCB and SMA connector losses of
0.11 dB subtracted
f1 = 2440 MHz, f2 = 2441MHz,
Pin = -25 dBm
f1 = 2440 MHz, f2 = 2441MHz,
Pin = -25 dBm
Unconditionally stable from 0 to
10GHz
2012-11-30
BFP740ESD
Low Noise Amplifier for Wireless LAN 2.4GHz Application
Measured Graphs
4
Measured Graphs
Insertion Power Gain
25
20
15
2400 MHz
19 dB
2440 MHz
18.9 dB
2500 MHz
18.8 dB
10
5
0
2100
Figure 3
2400
Frequency (MHz)
2700
Narrowband Isertion gain of BFP740ESD for WLAN 2.4GHz Application
Insertion Power Gain WideBand
25
20
2440 MHz
18.9 dB
15
10
5
0
100
Figure 4
600 1100 1600 2100 2600 3100 3600 4100 4600 5100 56006000
Frequency (MHz)
Wideband power gain of BFP740ESD for WLAN 2.4GHz Application
Application Note AN295, Rev. 1.0
9 / 17
2012-11-30
BFP740ESD
Low Noise Amplifier for Wireless LAN 2.4GHz Application
Measured Graphs
Input Matching
0
-5
2440 MHz
-10.3 dB
-10
-15
0
2000
4000
6000
Frequency (MHz)
Figure 5
Input Matching of BFP740ESD for WLAN 2.4GHz Application
Output Matching
0
-5
2440 MHz
-11 dB
-10
-15
-20
0
2000
4000
6000
Frequency (MHz)
Figure 6
Output Matching of BFP740ESD for WLAN 2.4GHz Application
Application Note AN295, Rev. 1.0
10 / 17
2012-11-30
BFP740ESD
Low Noise Amplifier for Wireless LAN 2.4GHz Application
Measured Graphs
Reverse Isolation
-20
-25
-30
2440 MHz
-26.1 dB
-35
-40
-45
-50
0
2000
4000
6000
Frequency (MHz)
Figure 7
Reverse Isolation of BFP740ESD for WLAN 2.4GHz Application
Noise Figure
1
NF(dB)
0.8
0.6
2440 MHz
0.74
0.4
0.2
0
2300
Figure 8
2350
2400
Frequency (MHz)
2450
2500
Noise Figure of BFP740ESD for WLAN 2.4GHz Application
Application Note AN295, Rev. 1.0
11 / 17
2012-11-30
BFP740ESD
Low Noise Amplifier for Wireless LAN 2.4GHz Application
Measured Graphs
Input 1dB Compression Point at 2440MHz
20
Gain(dB)
15
-20.0
18.6
-12.9
17.6
10
5
0
-20
-15
-10
-5
Pin [dBm]
Figure 9
Input 1 dB compression point of BFP740ESD for WLAN 2.4GHz Application
Output 3rd Order Intercept Point 2440MHz
0
Power (dBm)
-20
2439 MHz
-46.4
2440 MHz
-6.2
-40
-60
-80
-100
2438.5
Figure 10
2439.5
2440.5
Frequency (MHz)
2441.5
2442.5
Output Third Order Interpoint (OIP3) of BFP740ESD for WLAN 2.4GHz Application
Application Note AN295, Rev. 1.0
12 / 17
2012-11-30
BFP740ESD
Low Noise Amplifier for Wireless LAN 2.4GHz Application
Measured Graphs
Swp Max
2700MHz
2.
0
6
0.
0.8
1.0
Input Matching Smith
0.
4
0
3.
0
4.
5.0
0.2
10.0
5.0
4.0
3.0
2.0
1.0
0.8
0.6
0.4
0
0.2
10.0
-10.0
2
-0.
4
.0
-5.
0
-3
.0
Figure 11
.0
-2
Swp Min
2100MHz
-1.0
-0.8
-0
.6
.4
-0
Input matching of BFP740ESD for WLAN 2.4GHz Application in the Smith Chart
Swp Max
2700MHz
2.
0
6
0.
0.8
1.0
Output Matching Smith
0.
4
0
3.
0
4.
5.0
0.2
10.0
5.0
4.0
3.0
2.0
1.0
0.8
0.6
0.4
0
0.2
10.0
-10.0
2
-0.
-4
.0
-5.
0
-3
.0
Figure 12
.0
-2
-1.0
-0.8
-0
.6
.4
-0
Swp Min
2100MHz
Output matching of BFP740ESD for WLAN 2.4GHz Application in the Smith Chart
Application Note AN295, Rev. 1.0
13 / 17
2012-11-30
BFP740ESD
Low Noise Amplifier for Wireless LAN 2.4GHz Application
Other Miscellaneous Measurements
5
Other Miscellaneous Measurements
Stability k Factor
2
7134.1 MHz
1.015
1.5
1
0.5
0
10
5010
10010
15000
Frequency (MHz)
Figure 13
Stability factor k of BFP740ESD circuit for up to 10GHz
Stability Mu Factor
2
47.462 MHz
1.006
1.5
1
7134.1 MHz
1.013
0.5
MU1()
MU2()
0
10
Figure 14
2010
4010
6010
Frequency (MHz)
8010
10000
Stability factor µ1 and µ2 of BFP740ESD circuit for up to 10GHz
Application Note AN295, Rev. 1.0
14 / 17
2012-11-30
BFP740ESD
Low Noise Amplifier for Wireless LAN 2.4GHz Application
Evaluation Board
6
Evaluation Board
Figure 15
Populated PCB picture of BFP740ESD for WLAN 2.4GHz board (Emitter Degeneration
Length 0.4mm)
Vias
FR4, 0.2mm
Copper
35µm
Figure 16
FR4, 0.8mm
PCB layer stack
Application Note AN295, Rev. 1.0
15 / 17
2012-11-30
BFP740ESD
Low Noise Amplifier for Wireless LAN 2.4GHz Application
Author
7
Author
Xiang Li, Application Engineer of Business Unit “RF and Protection Devices”
Dr. Chih-I Lin, Senior Staff Engineer of Business Unit “RF and Protection Devices”
Application Note AN295, Rev. 1.0
16 / 17
2012-11-30
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