B GS 12S N 6 Per for man ce of S PD T R F Swi t c h Ultr a L ow Inser tion Los s Wi de band R F SP DT fo r U MT S, W CD M A an d LT E diversit y or Wi Fi a p plic atio ns Applic atio n N ote A N 332 Revision: Rev. 1.0 2015-01-19 RF and P r otecti on D evi c es Edition 2015-03-25 Published by Infineon Technologies AG 81726 Munich, Germany © 2015 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. 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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. BGS12SN6 Ultra Low Insertion Loss Wideband Applications Application Note AN332 Revision History: 2015-01-19 Previous Revision: prev. Rev. 0.0 Page Subjects (major changes since last revision) Updated text 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 AN332, Rev. 1.0 3 / 27 2015-01-19 BGS12SN6 Ultra Low Insertion Loss Wideband Applications List of Content, Figures and Tables Table of Content 1 Introduction ........................................................................................................................................ 6 2 2.1 2.2 2.3 2.4 BGS12SN6 Features .......................................................................................................................... 6 Main Features ...................................................................................................................................... 6 Functional Diagram .............................................................................................................................. 7 Pin Configuration .................................................................................................................................. 7 Pin Description ..................................................................................................................................... 7 3 3.1 3.2 Application .......................................................................................................................................... 8 Band Selection with RF CMOS Switch in Single-Ended Configuration ............................................... 8 Application Board ............................................................................................................................... 10 4 4.1 4.2 4.3 4.4 4.5 4.6 4.7 Small Signal Characteristics ........................................................................................................... 12 Measurement Results ........................................................................................................................ 12 Forward Transmission (measured on application board)................................................................... 13 Forward Transmission (probe measurements on device pads) ......................................................... 14 Wideband reflection RFin Port ........................................................................................................... 14 Wideband reflection RF Ports ............................................................................................................ 15 Wideband isolation RF1 ..................................................................................................................... 15 Wideband isolation RF2 ..................................................................................................................... 16 5 Intermodulation ................................................................................................................................ 17 6 Harmonic Generation ....................................................................................................................... 20 7 Power Compression Measurements on all RF Paths ................................................................... 23 8 8.1 8.2 8.3 Switching time .................................................................................................................................. 24 Measurement Specifications .............................................................................................................. 24 Measurement Setup ........................................................................................................................... 24 Measurement results .......................................................................................................................... 25 9 Authors .............................................................................................................................................. 26 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 BGS12SN6 Functional Diagram .......................................................................................................... 7 Pin configuration................................................................................................................................... 7 PCS/IMT band switching ...................................................................................................................... 8 LTE Band -1/Band -4 switching............................................................................................................ 8 3.5 GHz WiMAX (IEEE 802.16e) transceiver system .......................................................................... 9 Dual-band (2.4–6.0 GHz) WLAN (IEEE 802.11a/b/g/n), also MIMO applications ............................... 9 Layout of the application board .......................................................................................................... 10 Layout of de-embedding boards and single SMA connector ............................................................. 10 Forward transmission in order to measurement method ................................................................... 11 PCB layer information ........................................................................................................................ 11 Forward Transmission Curves of all RF Ports for LB and HB frequency range ................................ 13 Forward Transmission Curves of all RF Ports for HB and WLAN frequency range .......................... 13 Wideband Forward Transmission Curves of all RF Ports .................................................................. 14 Reflction RFin Port (50 MHz to 6 GHz) .............................................................................................. 14 Reflction RFin Port (50 MHz to 6 GHz) .............................................................................................. 15 Isolation RF1 (50 MHz to 6 GHz) ....................................................................................................... 15 Isolation RF2 (50 MHz to 6 GHz) ....................................................................................................... 16 Block diagram of RF Switch intermodulation ..................................................................................... 17 Test set-up for IMD Measurements for low power blocker signals .................................................... 18 Test set-up for IMD Measurements for medium and high power blocker signals .............................. 18 IMD2 and IMD3 results for Band I ...................................................................................................... 19 IMD Results for Band V ...................................................................................................................... 19 Set-up for harmonics measurement ................................................................................................... 20 Application Note AN332, Rev. 1.0 4 / 27 2015-01-19 BGS12SN6 Ultra Low Insertion Loss Wideband Applications List of Content, Figures and Tables Figure 24 Figure 25 Figure 26 Figure 27 Figure 28 Figure 29 Figure 30 Figure 31 nd 2 harmonic at fc=824 MHz ............................................................................................................... 21 rd 3 harmonic at fc=824 MHz ................................................................................................................ 21 nd 2 Harmonic at fc=1800 MHz............................................................................................................. 22 rd 3 Harmonic at fc=1800 MHz ............................................................................................................. 22 Power Compression Measurement Results at fc=824 MHz, 1700 MHz and 2600MHz ..................... 23 Switching Time and Rise/Fall Time .................................................................................................... 24 Switching Time Measurement Setup ................................................................................................. 24 Screenshots of Switching Time Measurement BGS12SN6 .............................................................. 25 List of Tables Table 1 Table 2 Table 3 Table 4 Table 5 Table 6 Table 7 Table 8 Pin Description (top view) .................................................................................................................... 7 Forward Transmission from RFIN Port to the Respective RF Port (dB) ............................................ 12 Reflection RFin Port to the Respective RF Port (dB) ........................................................................ 12 Reflection RF Port to the Respective RF Port (dB) ............................................................................ 12 Isolation RF1 (off state) to RF2 and RFin (dB) .................................................................................. 12 Isolation RF2 (off state) to RF1 and RFin (dB) .................................................................................. 12 Test conditions and specifications of IMD measurements ................................................................. 17 Switching time measurement results ................................................................................................. 25 Application Note AN332, Rev. 1.0 5 / 27 2015-01-19 BGS12SN6 Ultra Low Insertion Loss Wideband Applications Introduction 1 Introduction The BGS12SN6 RF MOS switch is designed for mid power and pre PA applications. Any of the 2 ports can be used as termination of the diversity antenna or Wifi application handling up to 30 dBm. 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 32 dBm, resulting in linear performance at all signal levels. The RF switch has a very low insertion loss of 0.26 dB in the Low Band (LB), 0.29 dB in the Mid Band (MB) and High Band (HB) and 0.56 dB in the 5GHz range (measured directly with probes on the package). Unlike GaAs technology, external DC blocking capacitors at the RF ports are only required if DC voltage is applied externally. The BGS12SN6 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 BGS12SN6 Features 2.1 Main Features 2 high-linearity TRx paths with power handling capability of up to 30 dBm High switching speed, ideal for WLAN and Bluetooth applications All ports fully symmetrical No external decoupling components required Very low insertion loss up to 6 GHz Low harmonic generation High port-to-port-isolation 0.1 to 6 GHz coverage High ESD robustness On-chip control logic Very small leadless and halogen free package TSLP-6-2 (0.7x1.1mm ) with super low height of 0.31 mm RoHS compliant package 2 Application Note AN332, Rev. 1.0 6 / 27 2015-01-19 BGS12SN6 Ultra Low Insertion Loss Wideband Applications BGS12SN6 Features 2.2 Functional Diagram Pass through to RF1 RFin RF1 RF2 Isolation to Ground GND Decoder +ESD Vdd Figure 1 Ctrl Application specific funcional diagram for RF1 active BGS12SN6 Functional Diagram The functional Diagram in Figure 1 shows a typical bahaviour of the BGS12SN6 in active state, meaning RF1 active and RF2 in isolation mode. This Daigram gives a short brief about the working princip of this SPDT. The BGS12SN6 in designed by an implementation of several series and shunt transistors to ground to optimize the RF signal parameter in points of isolations between active and non-active ports and the RF power capability of 32 dBm in maximum ratings. 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 AN332, Rev. 1.0 7 / 27 Ground RF port 1 Supply Voltage 2015-01-19 BGS12SN6 Ultra Low Insertion Loss Wideband Applications Application 3 Application 3.1 Band Selection with RF CMOS Switch in Single-Ended Configuration The number of LTE bands to support in a mobile phone is increasing rapidly worldwide. A simple way to support more bands in a mobile phone is to implement band selection function by adding a RF CMOS switch to existing transceiver/diversity ICs. Following two examples show band selection with the BGS12SN6, switching in singleended configuration, a WiMAX FE system and a typical WLAN Dual Band application using the BGS12SN6 as RF switch. UMTS PCS or IMT GSM900 Rx GSM1800 Rx GSM1900 Rx GSM850/900 Tx PA LPF GSM1800/1900 Tx RF Transceiver IC GSM850 Rx UMTS Cell PCS UMTS SPDT Switch PCS or IMT IMT Figure 3 PCS/IMT band switching Band 4 LNA SPDT Switch Band 1 Figure 4 LTE Transceiver IC LTE Band -1/Band -4 switching Figure 3 and Figure 4 are typical examples of band switching in a phone or tablet for transmitting and receivien path. Such an application, using BGS12SN6 as band selection switch supports a brider bandwith for data transfer by adding an extra band at the transceivers to overcome the bottleneck to get higher data rates and improve the system performance. Application Note AN332, Rev. 1.0 8 / 27 2015-01-19 BGS12SN6 Ultra Low Insertion Loss Wideband Applications Application WiMAX: 3.3 – 3.7 GHz BPF LNA Balun WiMAX SPDT Switch Single/Dual Band Power Detector Transceiver IC ESD Diode PA BPF Figure 5 Balun 3.5 GHz WiMAX (IEEE 802.16e) transceiver system 2.4 GHz LNA Dual-Band WLAN: 2.4 – 6 GHz RX Diplexer RXg RXa SPDT Switch TX1 TX Transceiver IC TXg 2.4 GHz PA ESD Diode RX1 5 GHz LNA RX TX Diplexer TXn Figure 6 RXn Power Detector 5 GHz PA TXa Dual-band (2.4–6.0 GHz) WLAN (IEEE 802.11a/b/g/n), also MIMO applications Thanks to the BGS12SN6 wideband RF performance, supporting a very lo insertion loss of around 0.4 dB to 0.7 dB upto 6 GHz, this SPDT is highly suitable for WiMAX (Figure 5) and WLAN (Figure 6) applications. Next to this performance wise system key parameter, the BGS12SN6 has a very fast RF rise time of about 70 ns. Application Note AN332, Rev. 1.0 9 / 27 2015-01-19 BGS12SN6 Ultra Low Insertion Loss Wideband Applications Application 3.2 Application Board Below is a picture of the evaluation board used for the measurements (Figure 7). 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). But be aware, this calibration/deembedding method is only working in a proper way up to 3 to 4 GHz. Upper frequencies, and the resulting influence of the pcb transition to the coaxial line of the SMA connector can not be deembedded in such a way. The calibration of the network analyser (NWA) is done in severall steps: - Perform full calibration on all NWA ports. - Attach empty SMA connector (with cutted RF line, Figure 8, left) at port 2 and perform “open” port extension. Turn port extensions on. - Connect the “half” de-embedding board (Figure 8 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 8 right board) In case, there is no NWA including this option for the deembedding available, please use the measured s2p file as a deembedding structure in any RF simulation environment @ all ports of the measured application board itself. Figure 7 Layout of the application board Figure 8 Layout of de-embedding boards and single SMA connector Application Note AN332, Rev. 1.0 10 / 27 2015-01-19 BGS12SN6 Ultra Low Insertion Loss Wideband Applications Application Device level measurements above 4 GHz are not feasible with this deembeding method. The reason is a very tiny resonance between 5 and 6 GHz. Behind this behavior is the transmission between the pcb RF trace and the SMA coaxial line. The capacitance and the inductance are not sufficient enough to reproduce with the deembedding method. A better way to improve the compensation of the pcb losses and phase shifts is to perform a full open port extension with an empty application board including phase and losses. But, this is a trade of for insertion loss measurement accuracy over frequency bandwith. That means, for lower frequencies up to 3 or 4 Ghz the deembedding method is more ecactly, for higher frequencies the open port extension method is more accurate, shown in Figure 9, because of fewer losses in kind of quality characteristics of the connector to pcb transition, but limited by the number of points and the NWA’s interpolation. As reference for the BGS12SN6 performance, probe measurements direclty on the package (brown and red curve) pads are show the graph below. Forward Transmission vs. measurement method -0.2 -0.3 Proposed Deembedding Method freequency range -0.4 [dB] -0.5 Both Methods acceptable -0.6 -0.7 RF1_open_port_extension_method RF2_open_port_extension_method -0.8 Proposed Open Port Extension Method freequency range RF1_probe_measuement RF2_probe_measurement -0.9 RF1_deembeding_method RF2_deembedding_method -1 0 2000 4000 6000 Frequency (MHz) Figure 9 Forward transmission in order to measurement method These small differences, depending on the measurement method, are only necessary for higly precise insertion loss measurement concerning the neededcorrectness of some 1/10 rather 1/100 of dB. The construction of the PCB is shown in Figure 10 and contains of 3 layers (35µm copper), one Signal RF layer, and two ground layers meaning RF ground DC ground. The Rodgers material defines the RF performance, the FR4 material is just use as a mechanical carrier in order to stability of the pcb. Vias Rodgers , 0.2mm Copper 35µm Figure 10 FR4, 0.7mm PCB layer information Application Note AN332, Rev. 1.0 11 / 27 2015-01-19 BGS12SN6 Ultra Low Insertion Loss Wideband Applications Small Signal Characteristics 4 Small Signal Characteristics The small signal characteristics are measured at room temperature (~25°C) with a Network analyzer including a Multiport System on application board. The NWA is set to an input Power of 0dBm, a 50 MHz to 4 GHz (measuring LB and MB) or 50 MHz to 6 GHz (measuring HB and WLAN) frequency range with an IF bandwith of 15 kHz. All ports are terminated with a 50 Ω load (provided from the measurement system directly) during the measurement. Device specific, the Vdd is set to 3.3 volts and the Vctrl to 3 volts. 4.1 Measurement Results In the following tables and graphs the most important RF parameter of the BGS12SN6 are shown. The markers are set to the most important frequencies in Low Band (up to 1 GHz), Mid Band (over 1 GHz up to 3 GHz) and 1 2 High Band (3 GHz to 4 GHz) for mobile communication applications and Wireless LAN (5 GHz) . Table 2 Forward Transmission from RFIN Port to the Respective RF Port (dB) Low Band Mid Band High Band WLAN Frequency (MHz) 824 915 1000 1575 1710 1910 2170 2400 2690 3400 3600 5200 5500 5800 RF1 RF2 Table 3 -0.26 -0.27 -0.27 -0.3 -0.31 -0.32 -0.34 -0.37 -0.38 -0.49 -0.5 -0.68 -0.77 -0.67 -0.27 -0.27 -0.28 -0.31 -0.32 -0.33 -0.36 -0.38 -0.41 -0.5 -0.52 -0.69 -0.76 -0.71 Reflection RFin Port to the Respective RF Port (dB) Low Band Mid Band High Band WLAN Frequency (MHz) 824 915 1000 1575 1710 1910 2170 2400 2690 3400 3600 5200 5500 5800 RF1 RF2 Table 4 -25.4 -24.8 -23.9 -20.6 -19.8 -19 -18.2 -17.6 -17 -15.4 -15.4 -18 -19.7 -20.9 -25.7 -24.9 -24.3 -21 -20.4 -19.8 -18.9 -18.4 -17.8 -16.1 -15.9 -17.9 -19.2 -20.1 Reflection RF Port to the Respective RF Port (dB) Low Band Mid Band High Band WLAN Frequency (MHz) 824 915 1000 1575 1710 1910 2170 2400 2690 3400 3600 5200 5500 5800 RF1 RF2 Table 5 Frequency (MHz) RF2 RFin Table 6 Frequency (MHz) RF1 RFin 1 2 -26.2 -25.6 -24.7 -21 -20.2 -19.3 -18.3 -17.6 -16.9 -14.9 -14.9 -17.4 -18.7 -20.7 -25.4 -24.7 -24 -20.7 -20.2 -19.6 -18.8 -18.1 -17.4 -15.6 -15.6 -16.8 -17.7 -19 Isolation RF1 (off state) to RF2 and RFin (dB) Low Band 824 915 1000 Mid Band 1575 1710 1910 2170 High Band 2400 2690 3400 3600 WLAN 5200 5500 5800 -46.5 -45.8 -44.7 -39.3 -38.7 -38.5 -35.3 -34.5 -33.5 -31 -29.3 -20.9 -20.8 -22.7 -41 -39.9 -39.2 -34.1 -33.5 -32.7 -30.6 -29.8 -28.9 -26.8 -25.6 -18.3 -18 -19.9 Isolation RF2 (off state) to RF1 and RFin (dB) Low Band 824 915 1000 Mid Band 1575 1710 1910 2170 High Band 2400 2690 3400 3600 WLAN 5200 5500 5800 -46.1 -45.1 -44.2 -39.6 -38.6 -37.4 -36.1 -34.5 -34.2 -30.9 -29.2 -20.9 -21.4 -24.1 -40.5 -39.5 -38.7 -34.1 -33.1 -31.9 -30.3 -29 -27.7 -25.6 -24.9 -17.8 -17.2 -18.7 Measured with open port extension deembedding method Measured with open port extension deembedding method Application Note AN332, Rev. 1.0 12 / 27 2015-01-19 BGS12SN6 Ultra Low Insertion Loss Wideband Applications Small Signal Characteristics 4.2 Forward Transmission (measured on application board) Forward Transmission RF Ports for LB and MB 0 -0.5 [dB] 824 MHz -0.2678 dB 915 MHz -0.2738 dB -1 2400 MHz -0.3775 dB 1575 MHz -0.3049 dB 1710 MHz -0.3102 dB 2170 MHz -0.3416 dB 2690 MHz -0.3819 dB 1910 MHz -0.3215 dB 1000 MHz -0.2756 dB -1.5 RF1 RF2 -2 0 1000 2000 3000 Frequency (MHz) Figure 11 Forward Transmission Curves of all RF Ports for LB and HB frequency range Forward Transmission RF Ports for HB and WLAN 0 3400 MHz -0.4873 dB 3600 MHz -0.5003 dB [dB] -0.5 5200 MHz -0.6769 dB -1 5500 MHz -0.7571 dB 5900 MHz -0.7371 dB -1.5 RF1 RF2 -2 3000 5000 6000 Frequency (MHz) Figure 12 Forward Transmission Curves of all RF Ports for HB and WLAN frequency range Application Note AN332, Rev. 1.0 13 / 27 2015-01-19 BGS12SN6 Ultra Low Insertion Loss Wideband Applications Small Signal Characteristics 4.3 Forward Transmission (probe measurements on device pads) Wideband Foreward Transmission up to 6 Ghz 0 2170 MHz -0.31 dB 1575 MHz -0.29 dB 2400 MHz -0.32 dB 824 MHz -0.26 dB -0.5 1910 MHz -0.3 dB 915 MHz -0.26 dB 1000 MHz 1710 MHz -0.3 dB -0.27 dB 5800 MHz -0.63 dB 3400 MHz -0.39 dB 2690 MHz -0.34 dB 3600 MHz -0.41 dB 5200 MHz -0.55 dB 5500 MHz -0.59 dB -1 -1.5 RF1 RF2 -2 0 2000 4000 6000 Frequency (MHz) Figure 13 Wideband Forward Transmission Curves of all RF Ports 4.4 Wideband reflection RFin Port Reflection RFin Port -10 3270 MHz -15.25 dB -15 [dB] -20 -25 -30 RFin_RF1 RFin_RF2 -35 0 Figure 14 1000 2000 3000 4000 Frequency (MHz) 5000 6000 Reflction RFin Port (50 MHz to 6 GHz) Application Note AN332, Rev. 1.0 14 / 27 2015-01-19 BGS12SN6 Ultra Low Insertion Loss Wideband Applications Small Signal Characteristics 4.5 Wideband reflection RF Ports Reflection RF Ports -10 -15 -20 [dB] 3624 MHz -14.78 dB -25 -30 RF1 RF2 -35 0 2000 4000 6000 Frequency (MHz) Figure 15 Reflction RFin Port (50 MHz to 6 GHz) 4.6 Wideband isolation RF1 Isolation_RF1 0 -20 -40 5461 MHz -17.81 dB -60 RF2_RF1 RF1_RFin -80 0 2000 4000 6000 Frequency (MHz) Figure 16 Isolation RF1 (50 MHz to 6 GHz) Application Note AN332, Rev. 1.0 15 / 27 2015-01-19 BGS12SN6 Ultra Low Insertion Loss Wideband Applications Small Signal Characteristics 4.7 Wideband isolation RF2 Isolation_RF2 0 -20 -40 5479 MHz -17.02 dB -60 -80 RF1_RF2 RF2_RFin -100 50 2050 4050 6000 Frequency (MHz) Figure 17 Isolation RF2 (50 MHz to 6 GHz) Application Note AN332, Rev. 1.0 16 / 27 2015-01-19 BGS12SN6 Ultra Low Insertion Loss Wideband Applications 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 18. The transmission (Tx) signal from the main antenna is coupled into the diversity antenna with 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 18 Block diagram of RF Switch intermodulation Special combinations of TX and Jammer signal are producing intermodulation products 2 nd rd and 3 order, which fall in the RX band and disturb the wanted RX signal. In Error! Reference source not found. frequencies for 3 bands and the linearity specifications for an undisturbed communication are given. Table 7 Test conditions and specifications of IMD measurements Band 1 TX Testcase FIN (MHz) PIN (dBm) CW IMD3 IMD2 low IMD2 high 1950 10 Interferer FIN (MHz) PIN (dBm) CW 1760 190 -15 4090 IMD product FIMD (MHz) 2140 Band 5 Testcase FIN (MHz) PIN (dBm) CW IMD3 IMD2 low IMD2 high 835 10 FIN (MHz) 790 45 1715 PIN (dBm) CW FIMD (MHz) -15 880 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 19 and Figure 21). Application Note AN332, Rev. 1.0 17 / 27 2015-01-19 BGS12SN6 Ultra Low Insertion Loss Wideband Applications Intermodulation For the RX / TX separation a professional duplexer with 80 dB isolation is used. In Figure 21 the results for High band are given. For each distortion scenario there is a min and a max value given. This variation is caused by a phase shifter connected between switch and duplexer. In the test set-up the phase shifter represents a no ideal matching of the switch to 50 Ohm. Load -20dB -6 dB IMD Product reference Plane Tx Signal Generator Power Amplifier Circulator Blocker Signal Duplexer Tunable Bandpass Filter -3 dB ANT Phase Shifter / Delay Line -6dB* -20dB DUT Tx ANT Tunable Bandpass Filter Signal Generator Rx Signal Analyzer Figure 19 -6 dB Power reference plane regarding Specification Test set-up for IMD Measurements for low power blocker signals Load -20dB -6 dB IMD Product reference Plane Tx Signal Generator Power Amplifier Circulator Blocker Signal Duplexer Tunable Bandpass Filter -3 dB ANT Phase Shifter / Delay Line DUT Tx -6 dB* -20 dB ANT Tunable Bandpass Filter Rx Load Signal Analyzer -6 dB Power reference plane regarding Specification -20dB Signal Generator Figure 20 Power Amplifier Circulator Test set-up for IMD Measurements for medium and high power blocker signals Application Note AN332, Rev. 1.0 18 / 27 2015-01-19 BGS12SN6 Ultra Low Insertion Loss Wideband Applications Intermodulation Band 1 IMD -95.00 -100.00 [dBm] -105.00 -110.00 RF1 -115.00 RF2 -120.00 -125.00 Figure 21 IMD2 and IMD3 results for Band I Band 5 IMD -95.00 -100.00 [dBm] -105.00 -110.00 -115.00 RF1 -120.00 RF2 -125.00 -130.00 Figure 22 IMD Results for Band V Application Note AN332, Rev. 1.0 19 / 27 2015-01-19 BGS12SN6 Ultra Low Insertion Loss Wideband Applications 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 33 dBm. With this high RF power at the input of the switch harmonics are generated. These harmonics (2 nd rd and 3 ) can disturb the other reception bands or cause distortion in other RF applications (GPS, WLan) within the mobile phone. Load -20dB Directional Coupler -20dB -3 dB Signal Generator Power Amplifier Circulator F = Ffundamantel Lowpass Filter Ffilter ≥ Ffundamental A measurement Pin (Ffundamental) Power meter B -3dB measurement Pout (Ffundamental) DUT Tx -10dB Signal Analyzer Highpass Filter Ffundamental << Ffilter ≤ Fharmonics Directional Coupler ANT -3 dB reference plane reference plane Pout (Fharmonic and Pin (Ffundamental) Ffundamental) Figure 23 Set-up for harmonics measurement nd rd The results for the harmonic generation at 824 MHZ are shown in Figure 24 (2 harmonic) and Figure 25 (3 harmonic) for all RF ports. At the x-axis the input power is plotted and at the y- axis the generated harmonics in dBm. Application Note AN332, Rev. 1.0 20 / 27 2015-01-19 BGS12SN6 Ultra Low Insertion Loss Wideband Applications Harmonic Generation nd Figure 24 2 harmonic at fc=824 MHz Figure 25 3 harmonic at fc=824 MHz rd Application Note AN332, Rev. 1.0 21 / 27 2015-01-19 BGS12SN6 Ultra Low Insertion Loss Wideband Applications Harmonic Generation nd Figure 26 2 Harmonic at fc=1800 MHz Figure 27 3 Harmonic at fc=1800 MHz rd Application Note AN332, Rev. 1.0 22 / 27 2015-01-19 BGS12SN6 Ultra Low Insertion Loss Wideband Applications Power Compression Measurements on all RF Paths 7 Power Compression Measurements on all RF Paths To judge the large signal capability the power compression is a usual measurement tool. The output the power is measured while increasing the input power. At a certain point the output power does not follow the input and the switch compresses the RF signal. In the diagram below (Figure 28) the IL is plotted versus the injected input power. The input power can be increased to 30 dBm and there is no compression visible on none of the RF ports. IL (dB) BGS12SN6 P0.1dB 1 0.9 0.8 0.7 0.6 0.5 0.4 0.3 0.2 0.1 0 P0.1dB 824 Mhz P0.1dB 1700 MHz P0.1dB 2600 MHZ 20 22 24 26 28 30 32 Pin (dBm) Figure 28 Power Compression Measurement Results at fc=824 MHz, 1700 MHz and 2600MHz 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 AN332, Rev. 1.0 23 / 27 2015-01-19 BGS12SN6 Ultra Low Insertion Loss Wideband Applications Switching time 8 Switching time 8.1 Measurement Specifications Switching On/ Off Time: 50% Trigger signal to 90 % RF Signal / 50% Trigger signal to 10% RF Signal Rise time / Fall time: 10% to 90% RF Signal / 90% to 10% RF Signal VCTRL 2 VCTRL tON 90% RF signal RF signal tOFF 10% RF signal 90% RF signal RF signal tOFF tON Figure 29 Switching Time and Rise/Fall Time 8.2 Measurement Setup Figure 30 Switching Time Measurement Setup Application Note AN332, Rev. 1.0 10% RF signal 24 / 27 2015-01-19 BGS12SN6 Ultra Low Insertion Loss Wideband Applications Switching time 8.3 Measurement results The switching Time measurement setup consist of one pulse generator which generates a sqare wave with 50% duty cycle and an amplitude of 1.8 Volts, an oscilloscope which can detect the 1 GHz signal and the 1 kHz signal and one Signal generator which is set to an output signal of 1GHz with a power level 10 dBm. If the oscilloscope cannot detect the 1 GHz signal of the RF path, due to small bandwith, it is possible to use a crystal oscillator in front of the oscilloscope (such a device detects any RF signal present at input and commutates that) so that the RF signal can be detected. Figure 31 Table 8 Screenshots of Switching Time Measurement BGS12SN6 Switching time measurement results BGS12SN6 Application Note AN332, Rev. 1.0 RF rise time (ns) Switching time (ns) 60 400 25 / 27 2015-01-19 BGS12SN6 Ultra Low Insertion Loss Wideband Applications Authors 9 Authors Andre Dewai, Senior Application Engineer of the Business Unit “RF and Protection Devices” Ralph Kuhn, Senior Staff Application Engineer of the Business Unit “RF and Protection Devices” Application Note AN332, Rev. 1.0 26 / 27 2015-01-19