BF R84 0L3 RH E SD BFR840L3RHESD SiGe:C Ultra Low Noise RF Transistor in Low Parts Count Wideband / Dual Band 2.4 – 5.8 GHz WLAN LNA Application „0201‟ case size passives < 1 microsecond Turn-On / Turn-Off Time 18.5 dB Gain, 1.1 dB Noise Figure at 2.4 GHz; 14.1 dB Gain, 1.4 dB Noise Figure at 5.8 GHz (For 802.11a / ac / b / g / n Wireless LAN Applications) Applic atio n N ote A N 292 Revision: Rev. 1.0 2012-08-14 RF and P r otecti on D evic es Edition 2012-08-14 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. BFR840L3RHESD BFR840L3RHESD 2.4 - 5.8 GHz Dualband WLAN LNA Application Note AN292 Revision History: 2012-08-14 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 AN292, Rev. 1.0 3 / 30 2012-08-14 BFR840L3RHESD BFR840L3RHESD 2.4 - 5.8 GHz Dualband WLAN LNA List of Content, Figures and Tables Table of Contents 1 Introduction ........................................................................................................................................ 5 3 Schematic ........................................................................................................................................... 7 2 Measured Graphs ............................................................................................................................... 9 3 Evaluation Board and Layout Information .................................................................................... 27 4 Author ................................................................................................................................................ 29 5 Remark .............................................................................................................................................. 29 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 Figure 21 Figure 22 Figure 23 Block Diagram of low-cost WLAN application with Dual Band LNA .................................................... 6 Schematic Diagram .............................................................................................................................. 7 Noise Figure, 2.4 – 6 GHz Wideband / Dual Band LNA ..................................................................... 9 Noise Figure, Tabular Data ................................................................................................................ 10 Amplifier Gain compression at 2400 MHz .......................................................................................... 11 Amplifier Gain Compression at 5825 MHz ........................................................................................ 12 Amplifier stability factor “µ1” ............................................................................................................... 13 Input Match of Broadband / Dual Band LNA ..................................................................................... 14 Input Matching of the Broadband / Dual Band LNA, Smith Chart ...................................................... 15 Wideband Gain of Amplifier, DC Power ON ...................................................................................... 16 Wideband Gain of Amplifier, DC POWER OFF ................................................................................. 17 Reverse Isolation, DC power ON ....................................................................................................... 18 Reverse Isolation, DC Power OFF ..................................................................................................... 19 Amplifier Wideband Output Return Loss ............................................................................................ 20 Amplifier Output Return Loss, Smith Chart ........................................................................................ 21 rd Amplifier Input 3 Order Intercept Point Measurement, 2400 MHz ................................................... 22 rd Amplifier Input 3 Order Intercept Point Measurement, 5825 MHz ................................................... 23 Diagram of setup for making amplifier turn-on and turn-off times...................................................... 24 Oscilloscope screen shot, amplifier turn-on time ............................................................................... 25 Oscilloscope screen-shot, amplifier turn-off time ............................................................................... 26 View of Entire PC Board .................................................................................................................... 27 Close-In View of LNA Section. ......................................................................................................... 28 PC Board Cross-Section Information. ................................................................................................ 29 List of Tables Table 1 Table 2 Summary of Measurement Results ...................................................................................................... 6 Bill-of-Materials..................................................................................................................................... 7 Application Note AN292, Rev. 1.0 4 / 30 2012-08-14 BFR840L3RHESD BFR840L3RHESD 2.4 - 5.8 GHz Dualband WLAN LNA 1 Introduction 1.1 Device Overview: BFR840L3RHESD Infineon Technologies‟ BFR840L3RHESD is a high gain, ultra low noise Silicon-GermaniumCarbon (SiGe:C) HBT device suitable for a wide range of Low Noise Amplifier (LNA) applications. This RF Transistor has integrated protection structures to guard against Electro Static Discharge (ESD) events up to 1.5kV per the Human Body Model (HBM), and these same structures also protect the transistor against damage caused by excessive RF input power levels up to +20 dBm. The device is housed in the RoHS-compliant, Halogen-free TSLP-3-9 leadless package, which is only 1.0 x 0.6 x 0.31mm. The 0.31mm package height makes this transistor a good choice for RF Module applications. 1.2 Circuitry The circuit shown is targeted for Wireless LAN (WLAN) 802.11a / ac / b / g / n applications where lowest possible cost, low external parts count, and high receiver sensitivity / long range are primary goals. “0201” case size passives are used througout. Resistive Feedback is used to achieve unconditional stability and a good broadband 50 ohm match at both input and output. Feedback also makes the amplifier more tolerant of component & device variation, as well as making the design more forgiving of variations in PC board layout. The price paid for using feedback is a slight increase in amplifier noise figure, as well as some decrease in gain. (The penalty paid in Noise Figure from the feedback is approximately 0.4 dB at 2.4 GHz, and ~0.3 dB at 5 – 6 GHz). The LNA may be used as either a single-band amplifier at 2.4 or at 5 – 6 GHz with no changes made to the element values, or the LNA may be used in a dualband configuration where both WLAN bands are amplified together in a single device, i.e. for legacy systems where Dual Band Dual Concurrent operation is not required (refer to Figure 1). This simplification and commonality allows the end user to use one LNA design across his or her different systems, at either WLAN frequency band, simplifying logistics and reducing design effort. Potential applications may include WLAN transceivers used in Access Points, laptop PCs, Tablets, Gaming Consoles, USB dongles, etc. Generally, LNA‟s for these applications must be able to switch on & off within about 1 microsecond or less. The charge storage (capacitance) used in this circuit is Application Note AN292, Rev. 1.0 5 / 30 2012-08-14 BFR840L3RHESD BFR840L3RHESD 2.4 - 5.8 GHz Dualband WLAN LNA minimized to reduce on / off times, and this LNA achieves a switching time of ~ 15 nanoseconds. One potential trade-off for reduced capacitance values is a reduction in Third Order Intercept (IP3) performance. The good wideband match of the LNA – with an input and output return loss of -10 dB or better across the entire 2.4 – 6 GHz frequency range makes integrating the amplifier with other system blocks (filters, switches, diplexers, etc.) faster, easier and more predictable, reducing risk and time-to-market. No external emitter degeneration is required. The LNA is unconditionally stable over the 50 MHz – 12 GHz frequency range. External parts count (not including BFR840L3RHESD transistor) is 8; 4 capacitors, 3 resistors, and 1 chip inductors. All passives are „0201‟ case size. At 2.4 GHz, the amplifier achieves ~ 18 dB gain with a Noise Figure of 1.1 dB, while at 5.8 GHz, the gain is ~ 14 dB with a Noise Figure of 1.4 dB. HPF 5 – 6 GHz Rx Broadband Antenna WLAN RF ASIC Rx Tx / Rx Switch 2.4 GHz Rx Dual Band WLAN LNA 2.4 – 5.8 GHz LPF Low-Cost LC Diplexer Tx Tx Path Figure 1 Table 1 Block Diagram of low-cost WLAN application with Dual Band LNA Summary of Measurement Results Application Note AN292, Rev. 1.0 6 / 30 2012-08-14 BFR840L3RHESD BFR840L3RHESD 2.4 - 5.8 GHz Dualband WLAN LNA 3 Schematic Diagram V All passives are "0201" case size cc = 3.0V J3 DC Connector Inductor L1 is MuRata LQP03T_02 Series Total of 8 external elements: 4 x "C" 3 x "R" 1 x "L" DC Operating Point @ T=25 C: V CC = 3.0 V I = 9.4 mA V CE(Q1) = 1.87 V I = 9.4 mA (nominal) 120 ohms (0201) R3 C4 33 pF (0201) R1 33K (0201) R2 1K (0201) C2 10 pF (0201) L1 6.2 nH (0201) J1 J2 50 ohm trace RF INPUT Q1 50 ohm trace BFR840L3RHESD RF Transistor TSLP-3-9 Package C1 10 pF (0201) C3 1.8 pF (0201) BFR840L3RHESD Wideband / Dual Band WLAN Feedback LNA PCB = 840L3RHESD-120507 Rev A PC Board Material = Standard FR4 Layer spacing (top RF to internal ground plane): 0.010 inch / 0.25 mm Figure 2 Table 2 Symbol Schematic Diagram Bill-of-Materials Value Unit Size Manufacturer Comment C1 10 pF 0201 Various Input DC block C2 10 pF 0201 Various C3 1.8 pF 0201 Various DC block for RF Feedback path Output DC block; also influences input and output matching Application Note AN292, Rev. 1.0 7 / 30 2012-08-14 BFR840L3RHESD BFR840L3RHESD 2.4 - 5.8 GHz Dualband WLAN LNA Table 2 Bill-of-Materials Symbol Value Unit Size Manufacturer Comment C4 33 pF 0201 Various RF decoupling / lower frequency decoupling / blocking cap. Strongest influence on Turn-On / Turn-Off time. Value was minimized to speed up ON-OFF and OFF-ON time L1 6.2 nH 0201 Murata LQP03T series. RF choke at LNA output. Influences output match R1 33K Ohm 0201 Various DC biasing R2 1K Ohm 0201 Various R3 120 Ohm 0201 Various RF feedback resistor, output (collector) to input (base). Provides wideband matching, improves stability margin at price of reduced gain and slightly degraded noise figure (~ 0.1 dB). DC biasing. Drolps supply voltage below transistor‟s safe limit (VCE); also provides some DC negative feedback to stabilize DC operating point of transistor over temperature, hFE variation of transistor, etc. Q1 --- --- TSLP-3-9 Infineon 1.0 x 0.6 x 0.31mm Technologies J1, J2 --- --- --- J3 --- --- --- Application Note AN292, Rev. 1.0 Emerson – Johnson Tyco (AMP) 8 / 30 BFR840L3RHESD SiGe:C RF Transistor RF edge Mount SMA Female Connector, 142-0701-841 (Input, Output RF Connectors) 5 Pin DC connector header, MTA-100 Series, 640456-5 2012-08-14 BFR840L3RHESD BFR840L3RHESD 2.4 - 5.8 GHz Dualband WLAN LNA 2 Measured Graphs Noise Figure Plot. From Rohde & Schwarz FS-K3 + FSEM30. System preamplifier = MITEQ AFS3-00101200-22-10P-4-HS. Noise Source = Agilent 346A Figure 3 Noise Figure, 2.4 – 6 GHz Wideband / Dual Band LNA Application Note AN292, Rev. 1.0 9 / 30 2012-08-14 BFR840L3RHESD BFR840L3RHESD 2.4 - 5.8 GHz Dualband WLAN LNA Figure 4 Noise Figure, Tabular Data Application Note AN292, Rev. 1.0 10 / 30 2012-08-14 BFR840L3RHESD BFR840L3RHESD 2.4 - 5.8 GHz Dualband WLAN LNA Amplifier Compression Point Measurement, 2400 MHz Gain Compression at 2400 MHz, VCC = +3.0 V, I = 9.4mA, VCE = 1.9V, T = 25C: ZVB20 Vector Network Analyzer is set up to sweep input power to LNA in a “Power Sweep” at a fixed frequency of 2400 MHz. ZVB20 Port 1, which provides INPUT power to drive the LNA, has its power level calibrated (“SOURCE POWER CAL”) with the NRP-Z21 power sensor to ensure power level accuracy with the reference plane at the RF input connector of the amplifier. X-axis of VNA screen-shot below shows input power to LNA swept from –30 to –5 dBm. Input P1dB = -15.6 dBm Output P1dB = -15.6 dBm + (Gain-1dB) = -15.6 + 17.5 = +1.9 dBm Trc1 S21 dB Mag 1 dB / Ref 18 dB Cal int PCal Smo 1 M1 -29.64 dBm • M2 -15.62 dBm S21 20 18.600 dB 17.608 dB M119 M2 18 17 16 15 14 13 12 Ch1 Base Pwr Start -30 dBm Base Freq 2.4 GHz Stop -10 dBm 7/18/2012, 4:37 AM Figure 5 Amplifier Gain compression at 2400 MHz Application Note AN292, Rev. 1.0 11 / 30 2012-08-14 BFR840L3RHESD BFR840L3RHESD 2.4 - 5.8 GHz Dualband WLAN LNA Amplifier Compression Point Measurement, 5825 MHz Gain Compression at 5825 MHz, VCC = +3.0 V, I = 9.4mA, VCE = 1.9V, T = 25C: Input P1dB = -12.6 dBm Output P1dB = -12.6 dBm + (Gain-1dB) = -12.6 + 13.1 = +0.5 dBm* *(Used small signal gain from S21 plot on page 16, 14.1 dB gain ) Trc1 S21 dB Mag 1 dB / Ref 14 dB Cal int PCal Smo 1 M1 -29.64 dBm • M2 -12.56 dBm S21 16 14.022 dB 13.021 dB 15 M1 14 M2 13 12 11 10 9 8 Ch1 Base Pwr Start -30 dBm Base Freq 5.825 GHz Stop -10 dBm 7/18/2012, 4:40 AM Figure 6 Amplifier Gain Compression at 5825 MHz Application Note AN292, Rev. 1.0 12 / 30 2012-08-14 BFR840L3RHESD BFR840L3RHESD 2.4 - 5.8 GHz Dualband WLAN LNA Rohde and Schwarz ZVB Network Analyzer Calculates and plots stability factor “1” of the BFR840L3RHESD Wideband LNA in real time. Stability Factor 1 1 is defined as follows [1]: 1 - |S11|2 = | S22 – S11* det(S) | + |S21S12| The necessary & sufficient condition for Unconditional Stability is 1 > 1.0. In the plot, 1 > 1.0 over 10 MHz – 12 GHz; amplifier is Unconditionally Stable over 50 MHz – 12 GHz frequency range. Trc1 µ1 Lin Mag 100 mU/ Ref 1 U Cal Smo 1 M1 M2 M3 M4 • M5 µ1 1600 1500 2.400000 2.483500 4.900000 5.825000 1.405000 GHz GHz GHz GHz GHz 1.0437 1.0504 1.2391 1.2834 1.0107 U U U U U 1400 M4 1300 M3 1200 1100 M5 M2 M1 1000 900 800 Ch1 Base Freq Start 50 MHz Base Pwr -25 dBm Stop 12 GHz 7/18/2012, 1:28 AM Figure 7 Amplifier stability factor “µ1” Application Note AN292, Rev. 1.0 13 / 30 2012-08-14 BFR840L3RHESD BFR840L3RHESD 2.4 - 5.8 GHz Dualband WLAN LNA Note excellent input match of amplifier over entire 2.4 – 6 GHz frequency range. Trc1 S11 dB Mag 5 dB / Ref 0 dB Cal Smo 1 M1 M2 M3 • M4 S11 15 2.400000 2.483500 4.900000 5.825000 GHz GHz GHz GHz -12.832 -12.732 -11.898 -13.049 dB dB dB dB 10 5 0 -5 -10 M2 M1 M3 M4 -15 -20 -25 Ch1 Base Freq Start 50 MHz Base Pwr -25 dBm Stop 12 GHz 7/18/2012, 1:22 AM Figure 8 Input Match of Broadband / Dual Band LNA Application Note AN292, Rev. 1.0 14 / 30 2012-08-14 BFR840L3RHESD BFR840L3RHESD 2.4 - 5.8 GHz Dualband WLAN LNA Reference Plane = SMA RF Input Connector to PC Board. Trc1 S11 Smith Ref 1 U Cal Smo 1 1 S11 M1 2.400000 GHz 0.5 M2 M1 0 0.2 0.5 1 M3 2 33.535 j9.8169 651.00 2 M2 2.483500 GHz 33.916 j11.033 707.05 M3 4.900000 GHz 82.511 5 -j9.0865 3.575 • M4 5.825000 GHz 53.911 -j23.409 5 1.167 Ω Ω pH Ω Ω pH Ω Ω pF Ω Ω pF M4 -5 -0.5 -2 -1 Ch1 Base Freq Start 50 MHz Base Pwr -25 dBm Stop 12 GHz 7/18/2012, 1:22 AM Figure 9 Input Matching of the Broadband / Dual Band LNA, Smith Chart Application Note AN292, Rev. 1.0 15 / 30 2012-08-14 BFR840L3RHESD BFR840L3RHESD 2.4 - 5.8 GHz Dualband WLAN LNA Trc1 S21 dB Mag 5 dB / Ref 0 dB Cal Smo M1 M2 M3 • M4 S21 25 M1 M2 20 1 M3 2.400000 2.483500 4.900000 5.825000 GHz GHz GHz GHz 18.536 18.375 14.991 14.053 dB dB dB dB M4 15 10 5 0 -5 -10 -15 Ch1 Base Freq Start 50 MHz Base Pwr -25 dBm Stop 12 GHz 7/18/2012, 1:23 AM Figure 10 Wideband Gain of Amplifier, DC Power ON Application Note AN292, Rev. 1.0 16 / 30 2012-08-14 BFR840L3RHESD BFR840L3RHESD 2.4 - 5.8 GHz Dualband WLAN LNA Note: Gain change, ON to OFF, is ~ -38 dB at 2.4 GHz, and ~ -34 dB at 5.8 GHz Trc1 S21 dB Mag 5 dB / Ref 0 dB Cal Smo 1 M1 M2 M3 • M4 S21 10 2.400000 2.483500 4.900000 5.825000 GHz GHz GHz GHz -19.156 -19.180 -19.171 -20.121 dB dB dB dB 5 0 -5 -10 -15 M1 M2 M3 M4 -20 -25 -30 Ch1 Base Freq Start 50 MHz Base Pwr -25 dBm Stop 12 GHz 7/18/2012, 1:24 AM Figure 11 Wideband Gain of Amplifier, DC POWER OFF Application Note AN292, Rev. 1.0 17 / 30 2012-08-14 BFR840L3RHESD BFR840L3RHESD 2.4 - 5.8 GHz Dualband WLAN LNA Trc1 S12 dB Mag 5 dB / Ref 0 dB Cal Smo 1 M1 M2 M3 • M4 S12 5 2.400000 2.483500 4.900000 5.825000 GHz GHz GHz GHz -24.096 -24.068 -22.337 -21.447 dB dB dB dB 0 -5 -10 -15 M3 -20 M4 M1 M2 -25 -30 -35 Ch1 Base Freq Start 50 MHz Base Pwr -25 dBm Stop 12 GHz 7/18/2012, 1:24 AM Figure 12 Reverse Isolation, DC power ON Application Note AN292, Rev. 1.0 18 / 30 2012-08-14 BFR840L3RHESD BFR840L3RHESD 2.4 - 5.8 GHz Dualband WLAN LNA Trc1 S12 dB Mag 5 dB / Ref 0 dB Cal Smo 1 M1 M2 M3 • M4 S12 5 2.400000 2.483500 4.900000 5.825000 GHz GHz GHz GHz -19.057 -19.086 -19.010 -19.958 dB dB dB dB 0 -5 -10 -15 M1 M2 M3 M4 -20 -25 -30 -35 Ch1 Base Freq Start 50 MHz Base Pwr -25 dBm Stop 12 GHz 7/18/2012, 1:25 AM Figure 13 Reverse Isolation, DC Power OFF Application Note AN292, Rev. 1.0 19 / 30 2012-08-14 BFR840L3RHESD BFR840L3RHESD 2.4 - 5.8 GHz Dualband WLAN LNA Note excellent output match of amplifier over entire 2.4 – 6 GHz frequency range. This eases integration with other receiver chain blocks (i.e. filters, switches, etc.) Trc1 S22 dB Mag 5 dB / Ref 0 dB Cal Smo 1 M1 M2 M3 • M4 S22 10 2.400000 2.483500 4.900000 5.825000 GHz GHz GHz GHz -11.068 -10.954 -12.468 -12.738 dB dB dB dB 5 0 -5 M2 M1 -10 M3 M4 -15 -20 -25 -30 Ch1 Base Freq Start 50 MHz Base Pwr -25 dBm Stop 12 GHz 7/18/2012, 1:26 AM Figure 14 Amplifier Wideband Output Return Loss Application Note AN292, Rev. 1.0 20 / 30 2012-08-14 BFR840L3RHESD BFR840L3RHESD 2.4 - 5.8 GHz Dualband WLAN LNA Reference Plane = SMA RF Output Connector to PC Board. Trc1 S22 Smith Ref 1 U Cal Smo 1 1 S22 M1 2.400000 GHz 0.5 M2 M1 M4 0 0.2 0.5 1 2 33.495 j17.116 1.135 2 M2 2.483500 GHz 35.042 j19.804 1.269 M3 4.900000 GHz 34.234 5 -j12.823 2.533 • M4 5.825000 GHz 35.373 j13.686 5 373.95 Ω Ω nH Ω Ω nH Ω Ω pF Ω Ω pH M3 -5 -0.5 -2 -1 Ch1 Base Freq Start 50 MHz Base Pwr -25 dBm Stop 12 GHz 7/18/2012, 1:26 AM Figure 15 Amplifier Output Return Loss, Smith Chart Application Note AN292, Rev. 1.0 21 / 30 2012-08-14 BFR840L3RHESD BFR840L3RHESD 2.4 - 5.8 GHz Dualband WLAN LNA In-Band Third Order Intercept (IIP3) Test, 2400 MHz: Input Stimulus: f1=2400 MHz, f2=2401 MHz, -28 dBm each tone Input IP3 = -28+(45.0 / 2) = - 5.5 dBm Output IP3 = - 5.5 dBm + 18.5 dB gain = +13.0 dBm Figure 16 rd Amplifier Input 3 Order Intercept Point Measurement, 2400 MHz Application Note AN292, Rev. 1.0 22 / 30 2012-08-14 BFR840L3RHESD BFR840L3RHESD 2.4 - 5.8 GHz Dualband WLAN LNA Input Third Order Intercept (IIP3) Test, 5825 MHz: Input Stimulus: f1=5824 MHz, f2=5825 MHz, -28 dBm each tone Input IP3 = -28+(56.6 / 2) = +0.3 dBm Output IP3 = +0.3 dBm + 14.1 dB gain = +14.4 dBm Figure 17 rd Amplifier Input 3 Order Intercept Point Measurement, 5825 MHz Application Note AN292, Rev. 1.0 23 / 30 2012-08-14 BFR840L3RHESD BFR840L3RHESD 2.4 - 5.8 GHz Dualband WLAN LNA Block Diagram, Test Setup for Amplifier Turn-On / Turn Off time measurement Figure 18 Diagram of Setup for Making Amplifier Turn-On and Turn-Off Times. Application Note AN292, Rev. 1.0 24 / 30 2012-08-14 BFR840L3RHESD BFR840L3RHESD 2.4 - 5.8 GHz Dualband WLAN LNA Amplifier Turn On Time: Refer to oscilloscope screen-shot below. Upper trace (yellow, Channel 1) is the DC power supply turn-on step waveform whereas the lower trace (green, Channel 2) is the rectified RF output signal of the LNA stage. Amplifier turn-on time is aproximately 15 nanoseconds, or ~ 0.015 microseconds. Main source of time delay in the LNA turn-on event are the R-C time constants formed by (R3 * C4), etc. Charge storage has been minimized in this circuit so as to speed up turn on and turn off times. (Refer to Schematic diagram on page X). Figure 19 Oscilloscope Screen Shot, Amplifier Turn-On Time Application Note AN292, Rev. 1.0 25 / 30 2012-08-14 BFR840L3RHESD BFR840L3RHESD 2.4 - 5.8 GHz Dualband WLAN LNA Amplifier Turn-Off time Upper trace (Channel 1, yellow color) is the falling edge of the DC power supply voltage. Rectified RF output signal (Channel 2, lower green trace) takes about ~ 15 nanoseconds, or 0.015 microseconds, to settle out after power supply is turned off. Figure 20 Oscilloscope Screen-Shot, Amplifier Turn-Off Time Application Note AN292, Rev. 1.0 26 / 30 2012-08-14 BFR840L3RHESD BFR840L3RHESD 2.4 - 5.8 GHz Dualband WLAN LNA 3 Evaluation Board and Layout Information Figure 21 View of Entire PC Board Application Note AN292, Rev. 1.0 27 / 30 2012-08-14 BFR840L3RHESD BFR840L3RHESD 2.4 - 5.8 GHz Dualband WLAN LNA Note – five (5) 0.2mm diameter ground via holes are used for grounding (emitter connection) near top right corner of Q1. R2 is the feedback resisistor (RF Feedback). Figure 22 Close-In View of BFR840L3RHESD Wideband / Dualband LNA. Application Note AN292, Rev. 1.0 28 / 30 2012-08-14 BFR840L3RHESD BFR840L3RHESD 2.4 - 5.8 GHz Dualband WLAN LNA Note – standard low-cost “FR4” PC board material is used. PCB CROSS SECTION TOP LAYER (RF TRACES) 0.010 inch / 0.254 mm INTERNAL GROUND PLANE 0.031 inch / 0.787 mm ? LAYER FOR MECHANICAL RIGIDITY OF PCB, THICKNESS HERE NOT CRITICAL AS LONG AS TOTAL PCB THICKNESS DOES NOT EXCEED 0.045 INCH / 1.14 mm (SPECIFICATION FOR TOTAL PCB THICKNESS: 0.040 + 0.005 / - 0.005 INCH; 1.016 + 0.127 mm / - 0.127 mm ) BOTTOM LAYER Figure 23 PC Board Cross-Section Information. 4 Author Gerard Wevers,Senior Staff Applications Engineer of Business Unit “RF and Protection Devices”. 5 Remark The data graphs are exported from the Rohde and Schwarz ZVB network analyzer, FS-K3 Noise Figure Measurement system, or Agilent DSO6104A Oscilloscope. Application Note AN292, Rev. 1.0 29 / 30 2012-08-14 w w w . i n f i n e o n . c o m Published by Infineon Technologies AG AN292