Low Noise Amplifier with BFR840L3RHESD for 5 to 6 GHz WLAN Including 2.4GHz Rejection using 0201 SMDs Application Note AN290 Revision: Rev. 1.0 RF and Protection Devices
Edition Published by Infineon Technologies AG 81726 Munich, Germany 2012 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.
Application Note AN290 Revision History: Previous Revision: No previous revision 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 AN290, Rev. 1.0 3 / 21
List of Content, Figures and Tables Table of Content 1 Introduction... 5 1.1 Wi-Fi... 5 1.2 Device Overview: BFR840L3RHESD... 6 2 5 to 6 GHz WLAN LNA with 2.4 GHz Rejection using BFR840L3RHESD... 7 3 Overview... 8 4 Summary of Measurement Results... 8 5 Schematics... 9 6 Measured Graphs... 11 7 Evaluation Board and Layout Information... 18 8 Authors... 20 9 Remark... 20 List of Figures Figure 1 5 6 GHz Wi-Fi Wireless LAN (WLAN, IEEE802.11a/n/ac) and WiMAX (IEEE802.16e) Front-End 5 Figure 2 Schematic Diagram of the used Circuit... 9 Figure 3 Insertion Power Gain of the 5-6 GHz WLAN LNA with BFR840L3RHESD... 11 Figure 4 Wideband Insertion Power Gain of the 5-6 GHz WLAN LNA with BFR840L3RHESD... 11 Figure 5 Noise Figure of BFR840L3RHESD LNA for 5100-5900 MHz... 12 Figure 6 Reverse Isolation of the 5-6 GHz WLAN LNA with BFR840L3RHESD... 12 Figure 7 Input Matching of the 5-6 GHz WLAN LNA with BFR840L3RHESD... 13 Figure 8 Input Matching of the 5-6 GHz WLAN LNA with BFR840L3RHESD (Smith Chart)... 13 Figure 9 Output Matching of the 5-6 GHz WLAN LNA with BFR840L3RHESD... 14 Figure 10 Output Matching of the 5-6 GHz WLAN LNA with BFR840L3RHESD (Smith Chart)... 14 Figure 11 Wideband Stability k Factor of the 5-6 GHz WLAN LNA with BFR840L3RHESD... 15 Figure 12 Wideband Stability Mu Factor of the 5-6 GHz WLAN LNA with BFR840L3RHESD... 15 Figure 13 Input 1dB Compression Point of the BFR840L3RHESD Circuit at 5500 MHz... 16 Figure 14 Output 3 rd Order Intercept Point of BFR840L3RHESD at 5500 MHz... 16 Figure 15 OFF-Mode (Vcc = 0V, Icc = 0mA) S21 of the 5-6 GHz WLAN LNA with BFR840L3RHESD... 17 Figure 16 Input 1dB Compression Point of the BFR840L3RHESD Circuit at 2500 MH... 17 Figure 17 Photo of the BFR840L3RHESD 5-6 GHz WLAN LNA Evaluation Board... 18 Figure 18 Zoom-In on the BFR840L3RHESD 5-6 GHz WLAN LNA Evaluation Board... 18 Figure 19 Layout Proposal for RF Grounding of the 5-6 GHz WLAN LNA with BFR840L3RHESD... 19 Figure 20 PCB Layer Information... 19 List of Tables Table 1 Summary of Measurement Results... 8 Table 2 Bill-of-Materials... 10 Application Note AN290, Rev. 1.0 4 / 21
Introduction 1 Introduction 1.1 Wi-Fi Wireless Fidelity (Wi-Fi ) 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 SNR requirements for both the AP and the client are more stringent. For this kind of high-speed 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 ESD Diode SPDT Switch BPF Power Detector PA WLAN/ WiMAX Transceiver IC Figure 1 5 6 GHz Wi-Fi Wireless LAN (WLAN, IEEE802.11a/n/ac) and WiMAX (IEEE802.16e) Front- End Application Note AN290, Rev. 1.0 5 / 21
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 with RFswitches, TVS-diodes for ESD protection and RF Schottky diodes for power detection. 1.2 Device Overview: BFR840L3RHESD The BFR840L3RHESD 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 f T 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 BFR840L3RHESD 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 BFR840L3RHESD is housed in low-height 0.31mm TSLP-3-9 package specially fitting into modules. Further variants are available in industry standard visible-leads SOT343 package (BFP840ESD) and in flat-leads TSFP-4-1 package (BFP840FESD). Application Note AN290, Rev. 1.0 6 / 21
5 to 6 GHz WLAN LNA with 2.4 GHz Rejection using BFR840L3RHESD 2 5 to 6 GHz WLAN LNA with 2.4 GHz Rejection using BFR840L3RHESD This application note presents the measurement results of the Low Noise Amplifier using BFR840L3RHESD for 5100 MHz to 5900 MHz WLAN applications. The circuit schematic 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 10 passive 0201 size SMD components and brings gain from 14.9 db to 14.4 db over the frequency band. The noise figure varies from 1.08 db to 1.03 db (SMA and PCB losses are subtracted) over the complete frequency band. Moreover, 1dB compression point IP1dB at 2.4-2.5 GHz band is more than 0 dbm at input. The circuit achieves an input and output return loss of 11 db. Furthermore, the circuit is unconditionally stable from 10 MHz to 11 GHz. At 5.5 GHz, using two tones spacing of 1 MHz, the output third intercept point OIP3 reaches 16.3 dbm. Besides, we obtain 1dB input compression point IP1dB of -8.3 dbm. Application Note AN290, Rev. 1.0 7 / 21
Overview 3 Overview Device: BFR840L3RHESD Application: PCB Marking: BFR840L3RHESD TSLP-3-9 M120510 4 Summary of Measurement Results Table 1 Summary of Measurement Results Parameter Symbol Value Unit Note/Test Condition DC Voltage Vcc 3.0 V DC Current Icc 9.2 ma Frequency Range Freq 2500 5100 5500 5900 MHz Gain G 1.6 14.9 14.5 14.4 db Noise Figure NF 1.05 1.03 1.05 db Input Return Loss RLin 11.9 11.7 11 db Output Return Loss RLout 15 18.3 21 db Reverse Isolation IRev 22.9 22.4 21.8 db Input P1dB IP1dB 0-8.3 dbm Output P1dB OP1dB 0.6 +5.2 dbm Input IP3 IIP3 +1.8 dbm Output IP3 OIP3 +16.3 dbm Stability k > 1.0 -- SMA and PCB losses (~0.15 db) are subtracted Power @ Input: -25 dbm f 1 = 5500 MHz, f 2 = 5501 MHz Stability measured from 10MHz to 11GHz Application Note AN290, Rev. 1.0 8 / 21
Schematics 5 Schematics V cc = 3.0 V J3 DC Connector R3 120 ohms I = 9.2 ma C4 33pF All passives are 0201 case size Inductor L1 LQP03T Series Capacitors GRM Series C3 0.3pF J1 RF Port1 INPUT C1 22pF R1 33k Ohms R2 27 ohms Q1 BFR840L3RHESD L1 3.8nH C2 18pF J2 RF Port2 OUTPUT C5 2.2pF L2 1.8nH A proper RF grounding is required to ensure the LNA performance. Please refer to Chapter 7 for the layout proposal. Figure 2 Total externals Count = 10 Inductors = 2 (LQP03T Series) Resistors = 3 Capacitors = 5 Schematic Diagram of the used Circuit PCB Marking= BFR840L3RHESD TSLP-3-9 M120510 PCB Board Material = Standard FR4 Layer spacing (top RF to internal ground plane): 0.2 mm Application Note AN290, Rev. 1.0 9 / 21
Schematics Table 2 Bill-of-Materials Symbol Value Unit Size Manufacturer Comment C1 22 pf 0201 Various Input DC block C2 18 pf 0201 Various Output DC block C3 0.3 pf 0201 Various Output matching. Influence the input matching as well. C4 33 pf 0201 Various RF decoupling / blocking cap C5 2.2 pf 0201 Various 2.4 GHz rejection L1 3.8 nh 0201 Murata LQP03T series Output matching and biasing to the Collector L2 1.8 nh 0201 Murata LQP03T series 2.4 GHz rejection R1 33 kω 0201 Various DC biasing R2 27 Ω 0201 Various Stability improvement R3 120 Ω 0201 Various DC biasing (provides DC negative feedback to stabilize DC operating point over temperature variation, transistor h FE variation, etc.) Q1 TSLP-3-9 Infineon Technologies BFR840L3RHESD SiGe:C Heterojunction Bipolar RF Transistor Application Note AN290, Rev. 1.0 10 / 21
Measured Graphs 6 Measured Graphs 17 Insertion Power Gain InBand 16 15 5100 MHz 14.9 db 5900 MHz 14.4 db 14 13 4000 4500 5000 5500 6000 6500 7000 Frequency (MHz) Figure 3 Insertion Power Gain of the 5-6 GHz WLAN LNA with BFR840L3RHESD 20 Insertion Power Gain WideBand 15 10 5100 MHz 14.9 db 5900 MHz 14.4 db 5 2500 MHz 1.61 db 0-5 2400 MHz -9.32 db -10 2000 2500 3000 3500 4000 4500 5000 5500 6000 6500 7000 7500 8000 Frequency (MHz) Figure 4 Wideband Insertion Power Gain of the 5-6 GHz WLAN LNA with BFR840L3RHESD Application Note AN290, Rev. 1.0 11 / 21
NF(dB) BFR840L3RHESD Measured Graphs 1.4 Noise Figure 1.3 1.2 1.1 5500 MHz 1.03 db 5800 MHz 1.08 db 1 0.9 5100 MHz 1.05 db 5900 MHz 1.05 db 0.8 0.7 5100 5300 5500 5700 5900 Frequency (MHz) Figure 5 Noise Figure of BFR840L3RHESD LNA for 5100-5900 MHz 60 Reverse Isolation 50 40 30 5100 MHz 22.9 db 5900 MHz 21.8 db 20 10 0 4000 4500 5000 5500 6000 6500 7000 Frequency (MHz) Figure 6 Reverse Isolation of the 5-6 GHz WLAN LNA with BFR840L3RHESD Application Note AN290, Rev. 1.0 12 / 21
0 BFR840L3RHESD Measured Graphs -1.0 0.2 0.4 0.6 0.8 2.0 3.0 4.0 5.0 10.0-8 Input Matching -9-10 -11 5100 MHz -11.9 db 5900 MHz -11.1 db -12-13 -14 4000 4500 5000 5500 6000 6500 7000 Frequency (MHz) Figure 7 Input Matching of the 5-6 GHz WLAN LNA with BFR840L3RHESD 0.6 Input Matching Smith 0.8 1.0 1.0 Swp Max 7000MHz 2.0 0.4 3.0 4.0 5.0 0.2 10.0-0.2 5900 MHz r 0.568741 x 0.053913 5100 MHz r 0.602395 x -0.086714-10.0-5.0-4.0-0.4-3.0-2.0-0.6-0.8 Swp Min 3500MHz Figure 8 Input Matching of the 5-6 GHz WLAN LNA with BFR840L3RHESD (Smith Chart) Application Note AN290, Rev. 1.0 13 / 21
0 BFR840L3RHESD Measured Graphs -1.0 0.2 0.4 0.6 0.8 2.0 3.0 4.0 5.0 10.0-5 Output Matching -10 5100 MHz -15 db -15-20 5900 MHz -21 db -25 4000 4500 5000 5500 6000 6500 7000 Frequency (MHz) Figure 9 Output Matching of the 5-6 GHz WLAN LNA with BFR840L3RHESD 0.6 Output Matching Smith 0.8 1.0 1.0 Swp Max 7000MHz 2.0 0.4 3.0 0.2 5900 MHz r 0.86982 x -0.106505 4.0 5.0 10.0-0.2 5100 MHz r 0.765246 x -0.211879-10.0-5.0-4.0-0.4-3.0-2.0-0.6-0.8 Swp Min 3500MHz Figure 10 Output Matching of the 5-6 GHz WLAN LNA with BFR840L3RHESD (Smith Chart) Application Note AN290, Rev. 1.0 14 / 21
Measured Graphs 3 Stability k Factor 2 1 0 10 2010 4010 6010 8010 10000 Frequency (MHz) Figure 11 Wideband Stability k Factor of the 5-6 GHz WLAN LNA with BFR840L3RHESD 2 Stability Mu Factor 1.5 1 Mu2 factor 0.5 Mu1 factor 0 10 2010 4010 6010 8010 10000 Frequency (MHz) Figure 12 Wideband Stability Mu Factor of the 5-6 GHz WLAN LNA with BFR840L3RHESD Application Note AN290, Rev. 1.0 15 / 21
Power (dbm) Gain(dB) BFR840L3RHESD Measured Graphs 20 Input 1dB Compression Point at 5500 MHz 15 10-30 dbm 14.52 db -8.32 dbm 13.52 db 5 0-30 -25-20 -15-10 -5 0 Pin (dbm) Figure 13 Input 1dB Compression Point of the BFR840L3RHESD Circuit at 5500 MHz 0 Output 3rd Order Intercept Point -20 5500 MHz -10.5-40 5502 MHz -64.2-60 -80-100 5498.5 5499.5 5500.5 5501.5 5502.5 Frequency (MHz) Figure 14 Output 3 rd Order Intercept Point of BFR840L3RHESD at 5500 MHz Application Note AN290, Rev. 1.0 16 / 21
Gain(dB) BFR840L3RHESD Measured Graphs -16 OFF Mode S21-18 -20-22 5100 MHz -19.5 db 5900 MHz -21.3 db -24-26 4000 4500 5000 5500 6000 6500 7000 Frequency (MHz) Figure 15 OFF-Mode (Vcc = 0V, Icc = 0mA) S21 of the 5-6 GHz WLAN LNA with BFR840L3RHESD 5 Input 1dB Compression Point at 2500 MHz 3 1-1 -25.00 dbm 1.61 db -0.03 dbm 0.6 db -3-5 -25-20 -15-10 -5 0 5 Pin (dbm) Figure 16 Input 1dB Compression Point of the BFR840L3RHESD Circuit at 2500 MH Application Note AN290, Rev. 1.0 17 / 21
Evaluation Board and Layout Information 7 Evaluation Board and Layout Information Figure 17 Photo of the BFR840L3RHESD 5-6 GHz WLAN LNA Evaluation Board Figure 18 Zoom-In on the BFR840L3RHESD 5-6 GHz WLAN LNA Evaluation Board Application Note AN290, Rev. 1.0 18 / 21
Evaluation Board and Layout Information Figure 19 Layout Proposal for RF Grounding of the 5-6 GHz WLAN LNA with BFR840L3RHESD Vias FR4 Core, 0.2mm Copper 35µm FR4 Prepreg, 0.8mm Figure 20 PCB Layer Information Application Note AN290, Rev. 1.0 19 / 21
Authors 8 Authors Shamsuddin Ahmed, Application Engineer of Business Unit RF and Protection Devices Dr. Chih-I Lin, Senior Staff Engineer/Technical Marketing RF of Business Unit RF and Protection Devices 9 Remark The graphs are generated with the simulation program AWR Microwave Office. Application Note AN290, Rev. 1.0 20 / 21
w w w. i n f i n e o n. c o m Published by Infineon Technologies AG AN290