AN299

BF P840 F ES D
Low N oise A mpli fier for 5 to 6 G Hz
WLA N i ncl . 2.4 G Hz r ejec tio n w ith
BF P840 F ES D
Applic atio n N ote A N 299
Revision: Rev. 1.0
2012-12-21
RF and P r otecti on D evic es
Edition 2012-12-21
Published by
Infineon Technologies AG
81726 Munich, Germany
© 2013 Infineon Technologies AG
All Rights Reserved.
Legal Disclaimer
The information given in this document shall in no event be regarded as a guarantee of conditions or
characteristics. With respect to any examples or hints given herein, any typical values stated herein and/or any
information regarding the application of the device, Infineon Technologies hereby disclaims any and all
warranties and liabilities of any kind, including without limitation, warranties of non-infringement of intellectual
property rights of any third party.
Information
For further information on technology, delivery terms and conditions and prices, please contact the nearest
Infineon Technologies Office (www.infineon.com).
Warnings
Due to technical requirements, components may contain dangerous substances. For information on the types in
question, please contact the nearest Infineon Technologies Office.
Infineon Technologies components may be used in life-support devices or systems only with the express written
approval of Infineon Technologies, if a failure of such components can reasonably be expected to cause the
failure of that life-support device or system or to affect the safety or effectiveness of that device or system. Life
support devices or systems are intended to be implanted in the human body or to support and/or maintain and
sustain and/or protect human life. If they fail, it is reasonable to assume that the health of the user or other
persons may be endangered.
BFP840FESD
Low Noise Amplifier for 5-6GHz WLAN Applications
Application Note AN299
Revision History: 2012-12-21
Previous Revision: No previous version
Page
Subjects (major changes since last revision)
Trademarks of Infineon Technologies AG
AURIX™, C166™, CanPAK™, CIPOS™, CIPURSE™, EconoPACK™, CoolMOS™, CoolSET™,
CORECONTROL™, CROSSAVE™, DAVE™, DI-POL™, EasyPIM™, EconoBRIDGE™, EconoDUAL™,
EconoPIM™, EconoPACK™, EiceDRIVER™, eupec™, FCOS™, HITFET™, HybridPACK™, I²RF™,
ISOFACE™, IsoPACK™, MIPAQ™, ModSTACK™, my-d™, NovalithIC™, OptiMOS™, ORIGA™,
POWERCODE™, PRIMARION™, PrimePACK™, PrimeSTACK™, PRO-SIL™, PROFET™, RASIC™,
ReverSave™, SatRIC™, SIEGET™, SINDRION™, SIPMOS™, SmartLEWIS™, SOLID FLASH™,
TEMPFET™, thinQ!™, TRENCHSTOP™, TriCore™.
Other Trademarks
Advance Design System™ (ADS) of Agilent Technologies, AMBA™, ARM™, MULTI-ICE™, KEIL™,
PRIMECELL™, REALVIEW™, THUMB™, µVision™ of ARM Limited, UK. AUTOSAR™ is licensed by
AUTOSAR development partnership. Bluetooth™ of Bluetooth SIG Inc. CAT-iq™ of DECT Forum.
COLOSSUS™, FirstGPS™ of Trimble Navigation Ltd. EMV™ of EMVCo, LLC (Visa Holdings Inc.). EPCOS™
of Epcos AG. FLEXGO™ of Microsoft Corporation. FlexRay™ is licensed by FlexRay Consortium.
HYPERTERMINAL™ of Hilgraeve Incorporated. IEC™ of Commission Electrotechnique Internationale. IrDA™
of Infrared Data Association Corporation. ISO™ of INTERNATIONAL ORGANIZATION FOR
STANDARDIZATION. MATLAB™ of MathWorks, Inc. MAXIM™ of Maxim Integrated Products, Inc.
MICROTEC™, NUCLEUS™ of Mentor Graphics Corporation. MIPI™ of MIPI Alliance, Inc. MIPS™ of MIPS
Technologies, Inc., USA. muRata™ of MURATA MANUFACTURING CO., MICROWAVE OFFICE™ (MWO) of
Applied Wave Research Inc., OmniVision™ of OmniVision Technologies, Inc. Openwave™ Openwave Systems
Inc. RED HAT™ Red Hat, Inc. RFMD™ RF Micro Devices, Inc. SIRIUS™ of Sirius Satellite Radio Inc.
SOLARIS™ of Sun Microsystems, Inc. SPANSION™ of Spansion LLC Ltd. Symbian™ of Symbian Software
Limited. TAIYO YUDEN™ of Taiyo Yuden Co. TEAKLITE™ of CEVA, Inc. TEKTRONIX™ of Tektronix Inc.
TOKO™ of TOKO KABUSHIKI KAISHA TA. UNIX™ of X/Open Company Limited. VERILOG™, PALLADIUM™
of Cadence Design Systems, Inc. VLYNQ™ of Texas Instruments Incorporated. VXWORKS™, WIND RIVER™
of WIND RIVER SYSTEMS, INC. ZETEX™ of Diodes Zetex Limited.
Last Trademarks Update 2011-11-11
Application Note AN299, Rev. 1.0
3 / 20
2012-12-21
BFP840FESD
Low Noise Amplifier for 5-6GHz WLAN Applications
List of Content, Figures and Tables
Table of Content
1
1.1
1.2
Introduction ........................................................................................................................................ 5
®
Overview of Wi-Fi Applications ........................................................................................................... 5
Device Overview: BFP840FESD .......................................................................................................... 6
2
5 to 6 GHz WLAN LNA with 2.4GHz Rejection using BFP840FESD .............................................. 7
3
3.1
3.2
3.3
Application Circuit and Performance ............................................................................................... 8
Overview .............................................................................................................................................. 8
Summary of Measurement Results ...................................................................................................... 8
Schematics ........................................................................................................................................... 9
4
Measured Graphs ............................................................................................................................. 10
5
Evaluaton Board and Layout Information ..................................................................................... 17
6
Authors .............................................................................................................................................. 19
7
Remark .............................................................................................................................................. 19
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
Figure 17
Figure 18
Figure 19
Figure 20
5-6 GHz Wi-Fi Wireless LAN (WLAN, IEEE802.11a/n/ac) .................................................................. 5
Schematic Diagram of the Application Circuit ...................................................................................... 9
In-Band Insersion Power Gain of the 5-6GHz WLAN LNA with BFP840FESD ................................. 10
Wideband Insersion Power Gain of the 5-6GHz WLAN LNA with BFP840FESD ............................. 10
Noise Figure of BFP840FESD LNA for 5100-5900 MHz ................................................................... 11
Reverse Isolation of the 5-6 GHz WLNA LNA with BFP840FESD .................................................... 12
Input Matching of the 5-6GHz WLAN LNA with BFP840FESD ......................................................... 12
Input Matching of the 5-6GHz WLAN LNA with BFP840FESD (Smith Chart) ................................... 12
Output Matching of the 5-6GHz WLAN LNA with BFP840FESD ....................................................... 13
Output Matching of the 5-6GHz WLAN LNA with BFP840FESD (Smith Chart) ................................ 13
Wideband Stability K Factor of the 5-6GHz WLAN LNA with BFP840FESD .................................... 14
Wideband Stability Mu Factor of the 5-6GHz WLAN LNA with BFP840FESD .................................. 14
Input 1dB Compression Point of the BFP840FESD Circuit at 5500MHz ........................................... 15
rd
Input 3 Order Intercept Point of the BFP840FESD Circuit at 5500MHz .......................................... 15
OFF-Mode(Vcc=0V, Icc=0mA) S21 of the 5-6GHz WLAN LNA with BFP840FESD ......................... 16
Input 1dB Compression Point of the BFP840FESD Circuit at 2400MHz .......................................... 16
Photo of the BFP840FESD 5-6GHz WLAN LNA Evaluation Board ................................................... 17
ZOOM-In Photo of the BFP840FESD 5-6GHz WLAN LNA Evaluation Board .................................. 17
Layout Proposal for the RF Grounding of the 5-6GHz WLAN LNA with BFP840FESD ................... 18
PCB Layer Information ....................................................................................................................... 18
List of Tables
Table 1
Table 2
Summary of Measurement Results ................................................................................................... 8
Bill-of-Materials..................................................................................................................................... 9
Application Note AN299, Rev. 1.0
4 / 20
2012-12-21
BFP840FESD
Low Noise Amplifier for 5-6GHz WLAN Applications
Introduction
1
Introduction
1.1
Overview of Wi-Fi® Applications
Wireless Fidelity (Wi-Fi®) or well-known as wireless LAN (WLAN) plays a major role in
today’s communications by enabling constant connection in the 2.4 GHz and 5 GHz bands
and broadband Internet access for users with laptops or devices equipped with wireless
network interface while roaming within the range of fixed access points (AP) or a public
hotspot. Different applications like home entertainment with wireless high-quality multimedia
signal transmission, home networking notebooks, mass data storages and printers implement
5 – 6 GHz Wi-Fi® into their system to offer high-speed wireless connectivity.
When wider coverage areas are needed and especially when a higher order modulation
scheme is used such as in emerging very high throughput wireless specifications like 256
Quadrature Amplitude Modulation (256QAM) in IEEE 802.11ac, the signal-to-noise-ratio
(SNR) requirements for both the AP and the client are more stringent. For this kind of highspeed high data rate wireless communication standards it is essential to ensure the quality of
the link path. Major performance criteria of these equipments have to be fulfilled: sensitivity,
strong signal capability and interference immunity. Below a general application diagram of a
WLAN system is shown.
WLAN/WiMAX:
4.9 – 5.9 GHz
BPF
LNA
SPDT
Switch
Power Detector
BPF
PA
WLAN/
WiMAX
Transceiver IC
ESD
Diode
Figure 1
5-6 GHz Wi-Fi Wireless LAN (WLAN, IEEE802.11a/n/ac)
Application Note AN299, Rev. 1.0
5 / 20
2012-12-21
BFP840FESD
Low Noise Amplifier for 5-6GHz WLAN Applications
Introduction
In order to increase the system sensitivity, an excellent low noise amplifier (LNA) in front
of the receiver is mandatory, especially in an environment with very weak signal strength
and because of the insertion loss of the SPDT switch and the Bandpass Filter (BPF) or
diplexer. The typical allowed receiver chain Noise Figure (NF) of approx. 2 dB can only be
achieved by using a high-gain low noise amplifier.
In addition, strong signal environment can exist when the equipment is next to a
transmitter. In that case, the LNA must be linear enough, i.e. have high 1dB compression
point. This avoids saturation, degradation of the gain and increased noise figure.
This application note is focusing on the LNA block, but Infineon does also support RFswitches, TVS-diodes for ESD protection and RF Schottky diodes for power detection.
1.2
Device Overview: BFP840FESD
The BFP840FESD is a discrete hetero-junction bipolar transistor (HBT) specifically
designed for high performance 5 GHz band low noise amplifier (LNA) solutions for Wi-Fi
connectivity applications. It combines the 80 GHz fT silicon-germanium:carbide (SiGe:C)
B9HFM process with special device geometry engineering to reduce the parasitic
capacitance
between
substrate
and
transistor
that
degrades
high-frequency
characteristics, resulting in an inherent input matching and a major improvement in power
gain 5 GHz band together with a low noise figure performance that is industry's best.
The BFP840FESD has an integrated 1.5kV HBM ESD protection which makes the device
robust against electrostatic discharge and extreme RF input power. The device offers its
high performance at low current and voltage and is especially well-suited for portable
battery powered applications in which energy efficiency is a key requirement.
The BFP840FESD is housed in flat-leads TSFP-4-1 package. Further variants are
available in industry standard visible-leads SOT343 package (BFP840ESD) and in the
low-height 0.31mm TSLP-3-9 package (BFR840L3RHESD) specially fitting into modules.
Application Note AN299, Rev. 1.0
6 / 20
2012-12-21
BFP840FESD
Low Noise Amplifier for 5-6GHz WLAN Applications
5 to 6 GHz WLAN LNA with 2.4GHz Rejection using BFP840FESD
2
5 to 6 GHz WLAN LNA with 2.4GHz Rejection using BFP840FESD
This application note presents the measurement results of the low noise amplifier using
BFP840FESD for 5100 MHz to 5900 MHz WLAN applications. The circuit shown in Figure
2 doesn’t require any external input matching elements. High rejection at 2.4 GHz band is
achieved using a LC notch filter at the input of the LNA.
It requires ten passive 0402 size SMD components and brings gain from 17.9 dB to 18.8
dB over the frequency band. The noise figure varies from 1.05 dB to 1.15 dB (SMA and
PCB losses are subtracted) over the complete frequency band. Moreover, 1dB
compression point IP1dB at 2.4 GHz band is 4.4 dBm at input.
The circuit achieves an input and output return loss of better than 10 dB. Furthermore, the
circuit is unconditionally stable from 10 MHz to 15 GHz.
At 5.5 GHz, using two tones spacing of 1 MHz, the output third order intercept point OIP3
reaches 17.2 dBm. Besides, we obtain input 1dB input compression point IP1dB of -10.5
dBm.
Application Note AN299, Rev. 1.0
7 / 20
2012-12-21
BFP840FESD
Low Noise Amplifier for 5-6GHz WLAN Applications
Application Circuit and Performance
3
Application Circuit and Performance
3.1
Overview
Device:
BFP840FESD
Application: Low Noise Amplifier for 5 to 6 GHz WLAN with 2.4GHz Rejection
PCB Marking: BFP840FESD TSFP-4 M12080702
3.2
Summary of Measurement Results
Table 1
Summary of Measurement Results
Parameter
Symbol
Value
Unit
DC Voltage
Vcc
3.0
V
DC Current
Icc
15
mA
Frequency Range
Gain
Freq
G
2400
-7.3
5100
18.8
5500
18.4
5900
17.9
MHz
dB
NF
--
1.05
1.10
1.15
dB
RLin
--
10.2
11.6
11.4
dB
Output Return
Loss
RLout
--
10.7
10.5
12.4
dB
Reverse Isolation
Input P1dB
Output P1dB
Input IP3
IRev
IP1dB
OP1dB
IIP3
-4.4
--
26.4
---
25.9
-10.5
6.9
-1.2
25.5
---
dB
dBm
dBm
dBm
Noise Figure
Input Return Loss
Note/Test Condition
SMA and PCB losses (~0.15
dB) are subtracted
Power @ Input: -30 dBm
Output IP3
Stability
OIP3
17.2
dBm
k
> 1.0
--
Application Note AN299, Rev. 1.0
8 / 20
f1= 5500 MHz, f2= 5501 MHz
Stability measured from
10MHz to 8GHz
2012-12-21
BFP840FESD
Low Noise Amplifier for 5-6GHz WLAN Applications
Application Circuit and Performance
3.3
Schematics
V
cc
= 3.0V
J2
DC Connector
R3
51 ohm
I = 14 mA
C4
33pF
C3 1pF
51ohms
R2
L1
2nH
R1
27Kohm
Q1
C2 1pF
RF
OUTPUT
BFP840FESD
C1
22pF
RF
INPUT
J3
J1
C5
1.5pF
A proper RF grounding is required to ensure the LNA
performance. Please refer to Chapter 7 for the layout
proposal.
L2
2.7nH
PCB Marking=BFP840FESD TSFP-4-1 M12080702
PCB Board Material= Standard FR4
Layer spacing(top RF to internal ground plane):0.2 mm
Figure 2
Table 2
Symbol
C1
C2
Schematic Diagram of the Application Circuit
Bill-of-Materials
Value
22
1.0
Unit
pF
pF
Size
0402
0402
Manufacturer
Various
Various
Comment
Input DC block
Output DC block & output matching
C3
1.0
pF
0402
Various
Output matching. Influence the input
matching as well.
C4
C5
L1
33
1.5
2.0
pF
pF
nH
0402
0402
0402
Various
Various
Murata LQP15series
RF decoupling / blocking cap
2.4 GHz rejection
Output matching and biasing to the
Collector
L2
R1
R2
R3
2.7
27
51
51
nH
kΩ
Ω
Ω
0402
0402
0402
0402
Murata LQP15 series
Various
Various
Various
2.4 GHz rejection
DC biasing
Stability improvement
TSFP4-1
Infineon Technologies
Q1
Application Note AN299, Rev. 1.0
9 / 20
DC biasing (provides DC negative
feedback to stabilize DC operating point
over temperature variation, transistor
hFE variation, etc.)
BFP840FESD SiGe:C Heterojunction
Bipolar RF Transistor
2012-12-21
BFP840FESD
Low Noise Amplifier for 5-6GHz WLAN Applications
Measured Graphs
4
Measured Graphs
Insertion Power Gain InBand
20
5100 MHz
18.8 dB
18
5500 MHz
18.4 dB
5900 MHz
17.9 dB
16
14
12
4000
Figure 3
4500
5000
5500
6000
Frequency (MHz)
6500
7000
In-Band Insersion Power Gain of the 5-6GHz WLAN LNA with BFP840FESD
Insertion Power Gain WideBand
20
15
5100 MHz 5500 MHz
18.8 dB
18.4 dB
5900 MHz
17.9 dB
10
5
0
-5
2400 MHz
-7.34 dB
-10
-15
2000 2500 3000 3500 4000 4500 5000 5500 6000 6500 7000 7500 8000
Frequency (MHz)
Figure 4
Wideband Insersion Power Gain of the 5-6GHz WLAN LNA with BFP840FESD
Application Note AN299, Rev. 1.0
10 / 20
2012-12-21
BFP840FESD
Low Noise Amplifier for 5-6GHz WLAN Applications
Measured Graphs
Noise Figure
2
NF(dB)
1.5
5500 MHz
1.1 dB
5100 MHz
1.05 dB
5900 MHz
1.15 dB
1
0.5
0
5100
Figure 5
5300
5500
Frequency (MHz)
5700
5900
Noise Figure of BFP840FESD LNA for 5100-5900 MHz
Reverse Isolation
0
-10
5100 MHz
-26.4 dB
-20
5500 MHz
-25.9 dB
5900 MHz
-25.5 dB
-30
-40
4000
4500
Application Note AN299, Rev. 1.0
5000
5500
6000
Frequency (MHz)
11 / 20
6500
7000
2012-12-21
BFP840FESD
Low Noise Amplifier for 5-6GHz WLAN Applications
Measured Graphs
Figure 6
Reverse Isolation of the 5-6 GHz WLNA LNA with BFP840FESD
Input Matching
-2
-4
-6
5100 MHz
-10.2 dB
-8
5500 MHz
-11.6 dB
5900 MHz
-11.4 dB
-10
-12
4000
Figure 7
4500
5000
5500
6000
Frequency (MHz)
6500
7000
Input Matching of the 5-6GHz WLAN LNA with BFP840FESD
Swp Max
7000MHz
2.
0
6
0.
0.8
1.0
Input Matching Smith
0.
4
5500 MHz
r 0.659729
x 0.283577
5100 MHz
r 0.555349
x 0.192007
5900 MHz 3.0
r 0.771871
.0
x 0.436442 4 0
5.
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 8
.0
-2
-1.0
-0.8
-0
.6
.4
-0
Swp Min
3500MHz
Input Matching of the 5-6GHz WLAN LNA with BFP840FESD (Smith Chart)
Application Note AN299, Rev. 1.0
12 / 20
2012-12-21
BFP840FESD
Low Noise Amplifier for 5-6GHz WLAN Applications
Measured Graphs
Output Matching
0
-10
5500 MHz
5900 MHz
-10.5 dB
-12.4 dB
5100 MHz
-10.7 dB
-20
-30
-40
-50
-60
4000
Figure 9
4500
5000
5500
6000
Frequency (MHz)
6500
7000
Output Matching of the 5-6GHz WLAN LNA with BFP840FESD
Swp Max
7000MHz
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
5100 MHz
r 1.11718
x -0.635948
2
-0.
.0
-2
-1.0
-0.8
-0
.6
-3
.0
Figure 10
4
.0
-5.
0
5500 MHz
r 1.02149
x -0.628442
.4
-0
-10.0
0.2
10.0
5900 MHz
r 0.955856
x -0.480283
Swp Min
3500MHz
Output Matching of the 5-6GHz WLAN LNA with BFP840FESD (Smith Chart)
Application Note AN299, Rev. 1.0
13 / 20
2012-12-21
BFP840FESD
Low Noise Amplifier for 5-6GHz WLAN Applications
Measured Graphs
Stability k Factor
2
1.5
1
0.5
0
100
5100
10100
15000
Frequency (MHz)
Figure 11
Wideband Stability K Factor of the 5-6GHz WLAN LNA with BFP840FESD
Stability Mu Factor
2
1.5
1
Mu2 factor
0.5
Mu1 factor
0
100
5100
10100
15000
Frequency (MHz)
Figure 12
Wideband Stability Mu Factor of the 5-6GHz WLAN LNA with BFP840FESD
Application Note AN299, Rev. 1.0
14 / 20
2012-12-21
BFP840FESD
Low Noise Amplifier for 5-6GHz WLAN Applications
Measured Graphs
Input 1dB Compression Point
20
-30 dBm
18.41 dB
Gain(dB)
15
-10.5 dBm
17.41 dB
10
5
0
-30
Figure 13
-25
-20
-15
Pin (dBm)
-10
-5
0
Input 1dB Compression Point of the BFP840FESD Circuit at 5500MHz
Output 3rd Order Intercept Point
0
5501 MHz
-6.98
Power (dBm)
-20
-40
5499 MHz
-55.3
-60
-80
-100
5498.5
Figure 14
5499.5
5500.5
Frequency (MHz)
5501.5
5502.5
rd
Input 3 Order Intercept Point of the BFP840FESD Circuit at 5500MHz
Application Note AN299, Rev. 1.0
15 / 20
2012-12-21
BFP840FESD
Low Noise Amplifier for 5-6GHz WLAN Applications
Measured Graphs
OFF Mode S21
-18
-20
-22
5100 MHz
-21.3 dB
5500 MHz
-20.9 dB
5900 MHz
-20.3 dB
-24
-26
4000
Figure 15
4500
5000
5500
6000
Frequency (MHz)
6500
7000
OFF-Mode(Vcc=0V, Icc=0mA) S21 of the 5-6GHz WLAN LNA with BFP840FESD
Input 1dB Compression Point 2G4
-5
-25 dBm
-7.3 dB
4.4 dBm
-8.3 dB
Gain(dB)
-10
-15
-20
-25
Figure 16
-20
-15
-10
-5
Pin (dBm)
0
5
10
Input 1dB Compression Point of the BFP840FESD Circuit at 2400MHz
Application Note AN299, Rev. 1.0
16 / 20
2012-12-21
BFP840FESD
Low Noise Amplifier for 5-6GHz WLAN Applications
Evaluaton Board and Layout Information
5
Evaluaton Board and Layout Information
Figure 17
Photo of the BFP840FESD 5-6GHz WLAN LNA Evaluation Board
Figure 18
ZOOM-In Photo of the BFP840FESD 5-6GHz WLAN LNA Evaluation Board
Application Note AN299, Rev. 1.0
17 / 20
2012-12-21
BFP840FESD
Low Noise Amplifier for 5-6GHz WLAN Applications
Evaluaton Board and Layout Information
Figure 19
Layout Proposal for the RF Grounding of the 5-6GHz WLAN LNA with BFP840FESD
Figure 20
PCB Layer Information
Application Note AN299, Rev. 1.0
18 / 20
2012-12-21
BFP840FESD
Low Noise Amplifier for 5-6GHz WLAN Applications
Authors
6
Authors
Edwin Guo, Application Engineer of Business Unit “RF and Protection Devices”
Shamsuddin Ahmed, Application Engineer of Business Unit “RF and Protection Devices”
7
Remark
The graphs are generated with the simulation program “Agilent - Advanced Design System”
Application Note AN299, Rev. 1.0
19 / 20
2012-12-21
w w w . i n f i n e o n . c o m
Published by Infineon Technologies AG
AN299
Similar pages