B GS 12P L 6 SP DT R F C MOS S w itc h For Hig h Po wer A p plic atio ns Applic atio n N ote A N 319 Revision: Rev. 1.0 2013-02-28 RF and P r otecti on D evic es Edition 2013-06-26 Published by Infineon Technologies AG 81726 Munich, Germany © 2013 Infineon Technologies AG All Rights Reserved. LEGAL DISCLAIMER THE INFORMATION GIVEN IN THIS APPLICATION NOTE IS GIVEN AS A HINT FOR THE IMPLEMENTATION OF THE INFINEON TECHNOLOGIES COMPONENT ONLY AND SHALL NOT BE REGARDED AS ANY DESCRIPTION OR WARRANTY OF A CERTAIN FUNCTIONALITY, CONDITION OR QUALITY OF THE INFINEON TECHNOLOGIES COMPONENT. THE RECIPIENT OF THIS APPLICATION NOTE MUST VERIFY ANY FUNCTION DESCRIBED HEREIN IN THE REAL APPLICATION. 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) WITH RESPECT TO ANY AND ALL INFORMATION GIVEN IN THIS APPLICATION NOTE. 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BGS12PL6 High Power Applications up to 35 dBm Application Note AN319 Revision History: 2013-02-28 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 AN319, Rev. 1.0 3 / 19 2013-02-28 BGS12PL6 High Power Applications up to 35 dBm List of Content, Figures and Tables Table of Content 1 Introduction ........................................................................................................................................ 6 2 2.1 2.2 2.3 2.4 BGS12PL6 Features ........................................................................................................................... 6 Main Features ...................................................................................................................................... 6 Functional Diagram .............................................................................................................................. 7 Pin Configuration .................................................................................................................................. 7 Pin Description ..................................................................................................................................... 7 3 3.1 3.2 3.3 Application .......................................................................................................................................... 8 LTE Band Switch .................................................................................................................................. 8 Antenna switch ..................................................................................................................................... 8 Application Board ................................................................................................................................. 9 4 4.1 4.2 4.3 4.4 4.5 Small Signal Characteristics ........................................................................................................... 10 Measurement Results ........................................................................................................................ 10 Forward Transmission ........................................................................................................................ 11 Reflection RFin Port ........................................................................................................................... 11 Isolation RF1 ...................................................................................................................................... 12 Isolation RF2 ...................................................................................................................................... 12 5 Intermodulation ................................................................................................................................ 13 6 Harmonic Generation ....................................................................................................................... 15 7 Power Compression Measurements on all RF Paths ................................................................... 17 8 Authors .............................................................................................................................................. 18 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 BGS12PL6 Functional Diagram ........................................................................................................... 7 Pin Configuration .................................................................................................................................. 7 Application LTE Switch ........................................................................................................................ 8 Antenna Switch with BGS12PL6 .......................................................................................................... 8 Photo of the Application Board ............................................................................................................. 9 Photos of De-embedding Boards ......................................................................................................... 9 PCB layer information .......................................................................................................................... 9 Forward Transmission Curves for RF Ports ....................................................................................... 11 Reflection RFin Port ........................................................................................................................... 11 Isolation RF1 ...................................................................................................................................... 12 Isolation RF2 ...................................................................................................................................... 12 Block Diagram of Intermodulation Measurement of RF Switch ......................................................... 13 Test Set-Up for IMD Measurements .................................................................................................. 14 IMD Results for Band I ....................................................................................................................... 14 IMD Results for Band V ...................................................................................................................... 14 Set-Up for Harmonics Measurement.................................................................................................. 15 nd 2 Harmonic at fc=830 MHz............................................................................................................... 15 rd 3 Harmonic at fc=830 MHz ............................................................................................................... 16 nd 2 Harmonic at fc=1800 MHz............................................................................................................. 16 rd 3 Harmonic at fc=1800 MHz ............................................................................................................. 16 Power Compression Measurement Results at fc=830 MHz ............................................................... 17 List of Tables Table 1 Table 2 Pin Description (top view) .................................................................................................................... 7 Forward Transmission from RFIN Port to the Respective RF Port with All Other Ports Terminated with 50Ω ............................................................................................................................................. 10 Application Note AN319, Rev. 1.0 4 / 19 2013-02-28 BGS12PL6 High Power Applications up to 35 dBm List of Content, Figures and Tables Table 3 Table 4 Table 5 Reflection RFin Port to the Respective RF Port with All Other Ports Terminated with 50Ω ............. 10 Reflection RF Port to the Respective RF Port with All Other Ports Terminated with 50Ω ................ 10 Test Conditions and Specifications of IMD Measurements ............................................................... 13 Application Note AN319, Rev. 1.0 5 / 19 2013-02-28 BGS12PL6 High Power Applications up to 35 dBm Introduction 1 Introduction The BGS12PL6 general purpose RF MOS power switch is designed to cover a broad range of high power applications from 30 MHz to 4 GHz, mainly in the transmit path of WCDMA and LTE mobile phones. The symmetric design of its single pole double throw (SPDT) configuration, as shown in Figure 1 offers high design flexibility. This single supply chip integrates on-chip CMOS logic driven by a simple, single-pin CMOS or TTL compatible control input signal. The 0.1 dB compression point exceeds the switch‟s maximum input power level of 35 dBm, resulting in linear performance at all signal levels. The RF switch has a very low insertion loss of 0.33 dB in the 1 GHz, 0.42 dB in the 2 GHz and 0.6 dB in the 3 GHz range. Unlike GaAs technology, external DC blocking capacitors at the RF ports are only required if DC voltage is applied externally. The BGS12PL6 RF switch is manufactured in Infineon‟s patented MOS technology, offering the performance of GaAs with the economy and integration of conventional CMOS including the inherent higher ESD robustness. 2 The device has a very small size of only 0.7x 1.1 mm and a maximum height of 0.4 mm. 2 BGS12PL6 Features 2.1 Main Features 2 high-linearity TRx paths with power handling capability of up to 35 dBm All ports fully symmetrical No external decoupling components required Very low insertion loss Very low harmonic generation High port-to-port-isolation 0.1 to 4 GHz coverage High ESD robustness On-chip control logic Small lead and halogen free package TSLP-6-4 (0.7 x 1.1 mm ) RoHS compliant package 2 Application Note AN319, Rev. 1.0 6 / 19 2013-02-28 BGS12PL6 High Power Applications up to 35 dBm BGS12PL6 Features 2.2 Functional Diagram Figure 1 BGS12PL6 Functional Diagram 2.3 Pin Configuration In Figure 2 the pin configuration in top view is given. Figure 2 Pin Configuration 2.4 Pin Description Table 1 Pin Description (top view) Pin No. Name Pin Type Function 1 RF2 I/O RF port 2 2 GND GND 3 RF1 I/O 4 Vdd PWR 5 RFIN I/O RF port In 6 CTRL I Control Pin Application Note AN319, Rev. 1.0 7 / 19 Ground RF port 1 Supply Voltage 2013-02-28 BGS12PL6 High Power Applications up to 35 dBm Application 3 Application 3.1 LTE Band Switch The next generation smart phones are required to support upto 15 different frequency bands and even more number of band combinations. Often the number of pins on the transceiver is limited. An RF switch can be used to expand the number of reception bands. One of the possible applications of this high power SPDT is an LTE band switch which can be used after the Power Amplfier (PA) as shown in the figure below. Main Antenna RF Transceiver IC SPDT Switch BGS12PL6 PA LTE SPNT Switch Figure 3 Application LTE Switch 3.2 Antenna switch Another application is the antenna switch for certain bands in LTE and CDMA. Antenna RF Transceiver IC LTE Figure 4 CDMA SPDT Switch BGS12PL6 Antenna Switch with BGS12PL6 Application Note AN319, Rev. 1.0 8 / 19 2013-02-28 BGS12PL6 High Power Applications up to 35 dBm Application 3.3 Application Board Below is a picture of the evaluation board used for the measurements (Figure 5). The board is designed so that all connecting 50 Ohm lines have the same length. In order to get accurate values for the insertion loss of the BGS12PL6 all influences and losses of the evaluation board, lines and connectors have to be eliminated. Therefore a separate de-embedding board, representing the line length is necessary (Figure 6). The calibration of the network analyser (NWA) is done in severall steps: - Perform full calibration on all NWA ports. - Attach empty SMA connector at port 2 and perform “open” port extension. Turn port extensions on. - Connect the “half” de-embedding board (Figure 6 left board) between port1 and port2, store this as a s-parameter (s2p) file. - Turn all port extentions off. - Load the stored s-parameter file as de-embedding file for all used NWA ports - Switch all port extentions on - Check insertion loss with the de-embedding through board (Figure 6 right board) Figure 5 Photo of the Application Board Figure 6 Photos of De-embedding Boards The construction of the PCB is shown in Figure 7. Vias Rodgers , 0.2mm Copper 35µm Figure 7 FR4, 0.8mm PCB layer information Application Note AN319, Rev. 1.0 9 / 19 2013-02-28 BGS12PL6 High Power Applications up to 35 dBm Small Signal Characteristics 4 Small Signal Characteristics The small signal characteristics are measured at 25 °C with a 4-port Network Analyzer. 4.1 Measurement Results In the following tables and graphs the most important RF parameters of the BGS12SL6 are shown. The markers are set to the most important frequencies of the WDCDMA system. Table 2 Forward Transmission from RFIN Port to the Respective RF Port with All Other Ports Terminated with 50Ω Frequency (MHz) RF Path RF1 RF2 Table 3 RF Path RF1 RF2 RF1 RF2 1000 1710 1910 2170 2690 -0.38 -0.37 -0.39 -0.38 -0.39 -0.38 -0.46 -0.44 -0.47 -0.46 -0.51 -0.49 -0.58 -0.57 824 915 1000 1710 1910 2170 2690 -29.1 -29.2 -27.8 -28.1 -27.7 -27.9 -25.3 -25.4 -24 -23.9 -22.2 -22 -20 -19.6 Reflection RF Port to the Respective RF Port with All Other Ports Terminated with 50Ω Frequency (MHz) RF Path 915 Reflection RFin Port to the Respective RF Port with All Other Ports Terminated with 50Ω Frequency (MHz) Table 4 824 824 915 1000 1710 1910 2170 2690 -29.8 -30.8 -29.4 -30.2 -29.3 -30.3 -26.2 -26.6 -25.3 -25.4 -23.7 -23.2 -20.2 -19.3 Application Note AN319, Rev. 1.0 10 / 19 2013-02-28 BGS12PL6 High Power Applications up to 35 dBm Small Signal Characteristics 4.2 Forward Transmission Forward Transmission RF Ports 0 -0.5 [dB] -1 824 MHz -0.3708 dB -1.5 2170 MHz -0.4914 dB 1710 MHz -0.4421 dB 915 MHz -0.3774 dB 1910 MHz -0.456 dB 2690 MHz -0.5731 dB -2 -2.5 RF1 RF2 -3 0 1000 2000 3000 Frequency (MHz) Figure 8 Forward Transmission Curves for RF Ports 4.3 Reflection RFin Port 4000 5000 Reflection RFin Port 0 [dB] -10 2690 MHz -19.56 dB -20 -30 RFin_RF1 RFin_RF2 -40 0 Figure 9 1000 2000 3000 Frequency (MHz) 4000 5000 Reflection RFin Port Application Note AN319, Rev. 1.0 11 / 19 2013-02-28 BGS12PL6 High Power Applications up to 35 dBm Small Signal Characteristics 4.4 Isolation RF1 Isolation_RF1 0 -20 -40 2690 MHz -25.22 dB -60 -80 RF2_RF1 RF1_RFin -100 0 Figure 10 Isolation RF1 4.5 Isolation RF2 1000 2000 3000 Frequency (MHz) 4000 5000 Isolation_RF2 0 -20 -40 2690 MHz -24.66 dB -60 -80 RF1_RF2 RF2_RFin -100 0 Figure 11 1000 2000 3000 Frequency (MHz) 4000 5000 Isolation RF2 Application Note AN319, Rev. 1.0 12 / 19 2013-02-28 BGS12PL6 High Power Applications up to 35 dBm Intermodulation 5 Intermodulation Another very important parameter of a RF switch is the large signal capability. One of the possible intermodulation scenarios is shown in Figure 12. The transmission (Tx) signal from the main antenna is coupled into the diversity antenna with high power.This signal (20 dBm) and a received Jammer signal (-15 dBm) are entering the switch. Coupled Tx Signal from main antenna Jammer (CW) Receiver Diversity Antenna RF Switch IMD Figure 12 Block Diagram of Intermodulation Measurement of RF Switch nd Special combinations of TX and Jammer signals produce 2 and 3rd order intermodulation products, which fall in the RX band and interfere with the wanted RX signal. In Table 5 frequencies for 3 bands and the intermodulation specifications for an undisturbed communication are given. Table 5 Test Conditions and Specifications of IMD Measurements Test Conditions (Tx = +20dBm, Bl = -15dBm,freq.in MHz,@25°C) Band Tx Freq. (MHz) (MHz) Rx Freq. (MHz) Intermodulation Specification 850 836.5 881.5 IMD2 Low Jammer 1 (MHz) 45 IMD3 IMD2 High Jammer 2 Jammer 3 (MHz) (MHz) 791.5 1718 IMD2 (dBm) IIP2 (dBm) IMD3 (dBm) IIP3 (dBm) -105 110 -105 65 1900 1880 1960 80 1800 3840 -105 110 -105 65 2100 1950 2140 190 1760 4090 -105 110 -105 65 The test setup for the IMD measurements has to provide a very high isolation between RX and TX signals. As an example the test set-up and the results for the high band are shown (Figure 13 and Figure 14). For the RX/TX separation a professional duplexer with 80 dB isolation is used. Application Note AN319, Rev. 1.0 13 / 19 2013-02-28 BGS12PL6 High Power Applications up to 35 dBm Intermodulation Figure 14 and Figure 15 show the results for Band I and Band V. For each distortion scenario there is a min. and a max. value given. This variation is caused by a phase shifter connected between the switch and the duplexer. In the test set-up the phase shifter represents a non-ideal matching of the switch to 50 Ohm. Load -20dB -3dB Tx K&L Mini Circuits (ZHL-30W-252 -S+) Signal Generator Power Amplifier Duplexer Tunable Bandpass Filter Circulator DUT ANT Phase Shifter / Delay Line TRx -20dB ANT K&L Tunable Bandpass Filter Signal Generator Rx K& L Tunable Bandpass Filter Signal Analyzer Figure 13 Power reference plane PTx = +20 dBm PBl = -15 dBm -3 dB Test Set-Up for IMD Measurements IMD Band - I IMD2 low IMD2 High IMD3 fb = 190 MHz fb = 4090 MHz fb = 1760 MHz Power RF-port Min Max Min Max Min Max P Tx = + 10dBm RF1 -113,46 -102,93 -118,42 -113,63 -133,97 -125,14 P int = - 15dBm RF2 -112,95 -102,45 -117,31 -113,76 -134,87 -126,04 P Tx = + 20dBm RF1 -105,52 -96,24 -111,64 -107,45 -118,05 -106,35 P int = - 15dBm RF2 -105,22 -95,58 -109,22 -106,19 -121,13 -108,86 Figure 14 IMD Results for Band I IMD Band - V IMD2 low IMD2 High IMD3 fb = 45 MHz fb = 1718 MHz fb = 791.5 MHz Power RF-port Min Max Min Max Min Max P Tx = + 10dBm RF1 -116,31 -106,04 -119,20 -110,94 -124,54 -116,64 P int = - 15dBm RF2 -115,84 -106,67 -116,66 -111,30 -126,02 -121,25 P Tx = + 20dBm RF1 -106,54 -97,06 -111,53 -105,13 -105,18 -98,54 P int = - 15dBm RF2 -107,77 -98,87 -108,43 -103,60 -108,59 -102,33 Figure 15 IMD Results for Band V Application Note AN319, Rev. 1.0 14 / 19 2013-02-28 BGS12PL6 High Power Applications up to 35 dBm Harmonic Generation 6 Harmonic Generation Harmonic generation is another important parameter for the characterization of a RF switch. RF switches have to deal with high RF levels up to 35 dBm. Harmonics are generated with such high RF power levels at the input of the switch. These harmonics (2 nd rd and 3 ) can disturb the reception of other bands or cause distortion in other RF applications (GPS, WLAN…) within the mobile phone. Load -20dB Directional Coupler -20dB Signal Generator Power Amplifier Circulator Tunable Bandpass Filter A Power meter Agilent E4419B -3dB B DUT ANT K&L Signal Analyzer Figure 16 -20dB Tunable Bandstop Filter Tx Directional Coupler Set-Up for Harmonics Measurement The results for the harmonic generation at 830 MHz are shown in Figure 17 (2 nd rd harmonic) and Figure 18 (3 harmonic) for all RF ports. In Figure 19 and Figure 20 the results for 1800 MHz are given. On the x-axis the input power is plotted and on the y- axis the generated harmonics in dBm. H2 LB 0 -10 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 H2 (dBm) -20 -30 -40 RF1 -50 RF2 -60 -70 -80 Figure 17 nd 2 Pin (dBm) Harmonic at fc=830 MHz Application Note AN319, Rev. 1.0 15 / 19 2013-02-28 BGS12PL6 High Power Applications up to 35 dBm Harmonic Generation H3 LB 0 -10 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 -20 H3 (dBm) -30 -40 RF1 -50 RF2 -60 -70 -80 -90 Figure 18 Pin (dBm) rd 3 Harmonic at fc=830 MHz H2 HB 0 -10 20 21 22 23 24 25 26 27 28 29 30 31 32 33 H2 (dBm) -20 -30 -40 RF1 -50 RF2 -60 -70 -80 Figure 19 nd 2 Pin (dBm) Harmonic at fc=1800 MHz H3 HB 0 -10 20 21 22 23 24 25 26 27 28 29 30 31 32 33 -20 H3 (dBm) -30 -40 RF1 -50 RF2 -60 -70 -80 -90 Figure 20 Pin (dBm) rd 3 Harmonic at fc=1800 MHz Application Note AN319, Rev. 1.0 16 / 19 2013-02-28 BGS12PL6 High Power Applications up to 35 dBm Power Compression Measurements on all RF Paths 7 Power Compression Measurements on all RF Paths To judge the large signal capability of a switch, „power compression‟ is a widely used measurement.The output power is measured while the input power increasing gradually. At a certain point the output power does not follow the input power and the switch compresses the RF signal. In the diagram below (Figure 21) the IL is plotted versus the injected input power. The input power can be increased up to 38 dBm and there is no compression visible on any of the RF ports. IL (dB) P0.1dB > Spec 1 0,9 0,8 0,7 0,6 0,5 0,4 0,3 0,2 0,1 0 P0.1dB > Spec 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 41 Pin (dBm) Figure 21 Power Compression Measurement Results at fc=830 MHz The measurements are done on large signal measurement setup which is not calibrated for Insertion Loss with high precision. So the values here may differ with the actual IL values earlier in this report. Application Note AN319, Rev. 1.0 17 / 19 2013-02-28 BGS12PL6 High Power Applications up to 35 dBm Authors 8 Authors Ralph Kuhn, Senior Staff Application Engineer of the Business Unit “RF and Protection Devices” Andre Dewai, Application Engineer of the Business Unit “RF and Protection Devices” Application Note AN319, Rev. 1.0 18 / 19 2013-02-28