AN10885 Doherty RF performance analysis using the BLF7G22LS-130 Rev. 02 — 25 February 2010 Application note Document information Info Content Keywords RF power transistors, Doherty architecture, LDMOS, power amplifier, RF performance, Digital PreDistortion (DPD), UMTS, W-CDMA, BLF7G22LS-130 Abstract This application note describes a state-of-the-art power amplifier design for UMTS base stations using the BLF7G22LS-130 LDMOS transistor AN10885 NXP Semiconductors Doherty RF performance analysis using the BLF7G22LS-130 Revision history Rev Date Description 02 20100225 Modifications 01 20100106 • • New template applied and Legal texts updated. • Figure 15 “BLF7G22LS-130 Doherty test circuit PCB layout” on page 11: Component Q1 rotated 180 degrees. Figure 8 “Power gain and efficiency as a function of output power” on page 7: Title and Figure notes updated. Initial version Contact information For more information, please visit: http://www.nxp.com For sales office addresses, please send an email to: [email protected] AN10885_2 Application note All information provided in this document is subject to legal disclaimers. Rev. 02 — 25 February 2010 © NXP B.V. 2010. All rights reserved. 2 of 15 AN10885 NXP Semiconductors Doherty RF performance analysis using the BLF7G22LS-130 1. Introduction This application note describes a state-of-the-art power amplifier design for UMTS base stations using the BLF7G22LS-130 LDMOS power transistor. The amplifier design characteristics and the test methods used to determine the RF performance are also described. The amplifier uses two BLF7G22LS-130 devices in a Doherty architecture on a Rogers 3006 PCB having a thickness of 0.64 mm (0.025”). The design ensures high-efficiency while maintaining a very similar peak power capability of two transistors combined. The input and output sections are internally matched, benefiting the amplifier design with high gain and good gain flatness and phase linearity over a wide frequency band. The BLF7G22LS-130 is a seventh generation LDMOS device using NXP Semiconductor’s advanced LDMOS process. 2. Test summary The amplifier was characterized under the following conditions: • Network analyzer measurements for power gain (Gp), delay (td) and Input Return Loss (IRL) at: – output power (PL) = 47 dBm – drain-source voltage (VDS) = 28 V – main power amplifier quiescent drain current (IDq) = 900 mA – gate-source voltage of peak amplifier (VGS (peak)) = 0.5 V • CDMA Interim Standard (IS-95) at VDS = 28 V, IDq = 900 mA and VGS = 0.5 V • 2-carrier W-CDMA (15 MHz spacing), VDS = 28 V, IDq = 900 mA and VGS (peak) = 0.5 V • Peak output power (P3dB) capability using CDMA IS95 signal, ratio of peak power to average power = 9.7 dB at 0.01 % probability, VDS = 28 V, IDq = 900 mA and VGS (peak) = 0.5 V • Output power 3 dB compression point using pulsed signal, width = 12 μs, 10 % duty cycle at VDS = 28 V, IDq = 900 mA and VGS (peak) = 0.5 V • Digital PreDistortion (DPD) measurements using a DPD system, 2-carrier W-CDMA signal, Peak-to-average ratio (PAR) = 7.5 dB at 0.01 % probability (total signal), VDS = 28 V, IDq = 900 mA, VGS (peak) = 0.5 V Table 1. AN10885_2 Application note Performance summary Frequency (GHz) Gp at 47 dBm (dB) IRL at P3dB 47 dBm pulsed (dB) 12 μs pulse width (dBm) IMD3 (no correction) at 47 dBm (dB) IMD3 with DPD at 47 dBm (dB) Drain efficiency (ηD) at 47 dBm (%) 2.11 17.2 −14.0 54.4 −31.3/−30.9 −60.2/−59.6 44.2 2.14 17.3 −15.5 54.4 −33.4/−33.0 −59.8/−58.4 42.9 2.17 17.2 −17.0 54.4 −33.8/−34.7 −59.4/−57.9 42.2 All information provided in this document is subject to legal disclaimers. Rev. 02 — 25 February 2010 © NXP B.V. 2010. All rights reserved. 3 of 15 AN10885 NXP Semiconductors Doherty RF performance analysis using the BLF7G22LS-130 3. RF performance 3.1 Network analyzer measurements Network analyzer measurements were performed under the following conditions: • • • • PL = 47 dBm VDS = 28 V IDq = 900 mA VGS (peak) = 0.5 V 001aal197 19 td (ns) 17 −4 3.0 15 −8 2.6 13 −12 2.2 11 −16 1.8 9 2.050 2.095 2.140 −20 2.185 2.230 f (GHz) Power gain and input return loss as a function of frequency AN10885_2 Application note 001aal199 3.4 IRL (dB) Gp (dB) Fig 1. 0 1.4 2.050 Fig 2. 2.095 2.140 2.185 2.230 f (GHz) Delay as a function of frequency All information provided in this document is subject to legal disclaimers. Rev. 02 — 25 February 2010 © NXP B.V. 2010. All rights reserved. 4 of 15 AN10885 NXP Semiconductors Doherty RF performance analysis using the BLF7G22LS-130 3.2 IS-95 measurements The IS-95 measurements were performed under the following conditions: • Bias: VDS = 28 V • IDq = 900 mA • VGS (peak) = 0.5 V 001aal200 20 100 ηD (%) Gp (dB) (1) (2) (3) 18 80 001aal227 −25 ACPR (dBc) (1) (2) (3) (4) (5) (6) −45 60 16 (4) (5) (6) 40 14 −65 (7) (8) (9) (10) (11) (12) 20 12 10 0 35 39 43 47 51 PL(AV) (dBm) −85 35 39 43 47 51 PL (dBm) (1) Gp = 2110 MHz. (1) 2110 MHz − 885 kHz. (2) Gp = 2140 MHz. (2) 2110 MHz + 885 kHz. (3) Gp = 2170 MHz. (3) 2140 MHz − 885 kHz. (4) ηD = 2110 MHz. (4) 2140 MHz + 885 kHz. (5) ηD = 2140 MHz. (5) 2170 MHz − 885 kHz. (6) ηD = 2170 MHz. (6) 2170 MHz + 885 kHz. (7) 2110 MHz − 1.98 MHz. (8) 2110 MHz + 1.98 MHz. (9) 2140 MHz − 1.98 MHz. (10) 2140 MHz + 1.98 MHz. (11) 2170 MHz − 1.98 MHz. (12) 2170 MHz + 1.98 MHz. Fig 3. Power gain and efficiency as a function of average output power, IS-95 AN10885_2 Application note Fig 4. Adjacent Channel Power Ratio (ACPR) as a function of output power All information provided in this document is subject to legal disclaimers. Rev. 02 — 25 February 2010 © NXP B.V. 2010. All rights reserved. 5 of 15 AN10885 NXP Semiconductors Doherty RF performance analysis using the BLF7G22LS-130 3.3 2-carrier W-CDMA measurements These measurements were performed under the following conditions: • • • • • Channel bandwidth = 3.84 MHz, spacing: 15 MHz Bias: VDS = 28 V IDq = 900 mA VGS (peak) = 0.5 V Heatsink temperature (Th) = 25 °C 001aal228 20 ηD (%) Gp (dB) 18 (1) (2) (3) 80 001aal229 0 100 IMD3 (dBc) −20 60 16 (4) (5) (6) (1) (2) (3) (4) (5) (6) 40 14 −40 20 12 10 0 35 39 43 47 51 PL(AV) (dBm) −60 35 37 39 41 (1) Gp = 2110 MHz. (1) 2110 MHz IMD3 low. (2) Gp = 2140 MHz. (2) 2110 MHz IMD3 high. (3) Gp = 2170 MHz. (3) 2140 MHz IMD3 low. (4) ηD = 2110 MHz. (4) 2140 MHz IMD3 high. (5) ηD = 2140 MHz. (5) 2170 MHz IMD3 low. (6) ηD = 2170 MHz. (6) 2170 MHz IMD3 high. Fig 5. Power gain and efficiency as a function of average output power, 2-carrier W-CDMA AN10885_2 Application note Fig 6. 43 45 47 49 PL (dBm) IMD3 as a function of output power, 2-carrier W-CDMA All information provided in this document is subject to legal disclaimers. Rev. 02 — 25 February 2010 © NXP B.V. 2010. All rights reserved. 6 of 15 AN10885 NXP Semiconductors Doherty RF performance analysis using the BLF7G22LS-130 3.4 Peak output power measurements Two methods were used to measure peak output power. • Using a standard IS-95 signal (PAR = 9.7 dB at 0.01 % probability on the CCDF), determining the output power where the PAR reaches 6.7 dB at 0.01 % probability on the CCDF, measured as the 3 dB compression point • Using the pulsed signal, measuring the 3 dB compression points The peak power measurements were performed under the following conditions: • Bias: VDS = 28 V • IDq = 900 mA • VGS (peak) = 0.5 V 001aal230 55.1 PL(M) (dBm) 001aal231 18 55 Gp (dB) 54.9 17 54.7 16 54.5 50 (4) (5) (6) ηD (%) 45 40 (1) (2) (3) 35 30 15 25 54.3 20 14 15 54.1 2100 10 55 13 2120 2140 2160 2180 35 40 f (MHz) 45 50 PL (dBm) (1) f = 2110 MHz. (2) f = 2140 MHz. (3) f = 2170 MHz. (4) f = 2110 MHz. (5) f = 2140 MHz. (6) f = 2170 MHz. Fig 7. Peak output power as a function of frequency AN10885_2 Application note Fig 8. Power gain and efficiency as a function of output power All information provided in this document is subject to legal disclaimers. Rev. 02 — 25 February 2010 © NXP B.V. 2010. All rights reserved. 7 of 15 AN10885 NXP Semiconductors Doherty RF performance analysis using the BLF7G22LS-130 3.5 DPD measurements The DPD measurements were performed using an in-house designed DPD system. The following DPD measurements were performed under the following conditions: • • • • fc = 2110 MHz DPD system: 2-carrier W-CDMA signal, spacing: 15 MHz VDS = 28 V, IDq = 900 mA, VGS (peak) = 0.5 V IMD3 at 47.23 dBm, 15 MHz offset (integrated bandwidth = 3.84 MHz) uncorrected (no DPD applied): −31.3 dB and −30.9 dB • IMD3 at 47.24 dBm, 15 MHz offset (integrated bandwidth = 3.84 MHz) corrected (DPD applied): −60.2 dB and −59.6 dB • IMD3 correction = 28.9 dB and 28.7 dB PL 40 (dBm) 30 20 10 0 −10 −20 −30 −40 −50 2085 2090 2095 2100 2105 2110 2115 2120 2125 2130 2135 f (MHz) 001aal232 IMD3 at 47.23 dBm, 0 dB attenuation. Fig 9. DPD uncorrected, fc = 2110 MHz 40 PL 30 (dBm) 20 10 0 −10 −20 −30 −40 −50 −60 2085 2090 2095 2100 2105 2110 2115 2120 2125 2130 2135 f (MHz) 001aal233 IMD3 at 47.24 dBm, 5 dB attenuation. Fig 10. DPD corrected, fc = 2110 MHz AN10885_2 Application note All information provided in this document is subject to legal disclaimers. Rev. 02 — 25 February 2010 © NXP B.V. 2010. All rights reserved. 8 of 15 AN10885 NXP Semiconductors Doherty RF performance analysis using the BLF7G22LS-130 The following DPD measurements were performed under the following conditions: • • • • fc = 2140 MHz DPD system: 2-carrier W-CDMA signal, spacing: 15 MHz VDS = 28 V, IDq = 900 mA, VGS (peak) = 0.5 V IMD3 at 47.16 dBm, 15 MHz offset (integrated bandwidth = 3.84 MHz) uncorrected: −33.4 dB and −33.0 dB • IMD3 at 47.14 dBm, 15 MHz offset (integrated bandwidth = 3.84 MHz) corrected: −59.8 dB and −58.4 dB • IMD3 correction = 26.4 dB and 25.4 dB 40 PL 30 (dBm) 20 10 0 −10 −20 −30 −40 −50 −60 2115 2120 2125 2130 2135 2140 2145 2150 2155 2160 2165 f (MHz) 001aal234 IMD3 at 47.16 dBm, 5 dB attenuation. Fig 11. DPD uncorrected, fc = 2140 MHz 40 PL 30 (dBm) 20 10 0 −10 −20 −30 −40 −50 −60 2115 2120 2125 2130 2135 2140 2145 2150 2155 2160 2165 f (MHz) 001aal235 IMD3 at 47.14 dBm, 5 dB attenuation. Fig 12. DPD corrected, fc = 2140 MHz AN10885_2 Application note All information provided in this document is subject to legal disclaimers. Rev. 02 — 25 February 2010 © NXP B.V. 2010. All rights reserved. 9 of 15 AN10885 NXP Semiconductors Doherty RF performance analysis using the BLF7G22LS-130 The following DPD measurements were performed under the following conditions: • • • • fc = 2170 MHz DPD system: 2-carrier W-CDMA signal, spacing:15 MHz VDS = 28 V, IDq = 900 mA, VGS (peak) = 0.5 V IMD3 at 47.04 dBm, 15 MHz offset (integrated bandwidth = 3.84 MHz) uncorrected: −33.8 dB and −34.7 dB • IMD3 at 47.13 dBm, 15 MHz offset (integrated bandwidth = 3.84 MHz) corrected: −59.4 dB and −57.9 dB • IMD3 correction = 25.6 dB and 23.2 dB 40 PL 30 (dBm) 20 10 0 −10 −20 −30 −40 −50 −60 2145 2150 2155 2160 2165 2170 2175 2180 2185 2190 2195 f (MHz) 001aal236 IMD3 at 47.04 dBm, 5 dB attenuation. Fig 13. DPD uncorrected, fc = 2170 MHz 40 PL 30 (dBm) 20 10 0 −10 −20 −30 −40 −50 −60 2145 2150 2155 2160 2165 2170 2175 2180 2185 2190 2195 f (MHz) 001aal237 IMD3 at 47.13 dBm, 5 dB attenuation. Fig 14. DPD corrected, fc = 2170 MHz AN10885_2 Application note All information provided in this document is subject to legal disclaimers. Rev. 02 — 25 February 2010 © NXP B.V. 2010. All rights reserved. 10 of 15 AN10885 NXP Semiconductors Doherty RF performance analysis using the BLF7G22LS-130 4. BLF7G22LS-130 Doherty test circuit R5 R3 R12 R2 C2 R7 Q1 C1 L1 R1 R13 C5 R14 L2 R11 R10 Q2 C4 C7 R6 D1 R8 C20 C10 C9 C15 C13 C17 R9 R4 C3 C8 C6 Q3 X1 C18 C17 C11 C12 C14 C16 R15 C6 Q3 C19 C3 R16 D1 R8 R9 R17 C7 Q2 R11 R5 R2 R12 R3 R7 C2 C1 Q1 R1 L1 C5 R13 C18 C13 C15 C9 C10 R10 C4 add metal R14 L2 C20 001aal238 Fig 15. BLF7G22LS-130 Doherty test circuit PCB layout AN10885_2 Application note All information provided in this document is subject to legal disclaimers. Rev. 02 — 25 February 2010 © NXP B.V. 2010. All rights reserved. 11 of 15 AN10885 NXP Semiconductors Doherty RF performance analysis using the BLF7G22LS-130 4.1 BLF7G22LS-130 Doherty test circuit components Table 2. BLF7G22LS-130 Doherty test circuit components Designator Description Part identifier Manufacturer Input PCB BLF7G22LS-130 Doherty PA Input-Rev1 Ohio circuits Output PCB Rogers 3006; εr = 6.15, ± 0.15; thickness 0.64 mm (0.025”); 35 μm (1 oz.) copper on each side; Ref. 1 on page 13 BLF7G22LS-130 Doherty PA Output-Rev1 Ohio circuits Q1 78L08 voltage regulator NJM#78L08UA-ND NJR Q2 2N2222 NPN transistor MMBT2222 Fairchild Q3 BLF7G22LS-130 BLF7G22LS-130 NXP Semiconductors R1, R14 9.1 Ω CRCW08059R09FKEA Vishay Dale R2, R3, R17 430 Ω CRCW0805432RFKEA Vishay Dale R4 75 Ω CRCW080575R0FKTA Vishay Dale R5 200 Ω, potentiometer 3214-1-201E Bourns R6 2 kΩ CRCW08052K00FKTA Vishay Dale R7, R12 1.1 kΩ CRCW08051K10FKEA Vishay Dale R8 11 kΩ CRCW080511K0FKEA Vishay Dale R9 5.1 Ω CRCW08055R11FKEA Vishay Dale R10 5.1 kΩ CRCW08055K10FKTA Vishay Dale R11 910 Ω CRCW0805909RFKTA Vishay Dale R13 499 Ω, 0.5 W CRCW2010499RFKEF Vishay Dale R15 SMT 2010 50 Ω RL - EMC R16 0Ω - Vishay Dale X1 3 dB, hybrid coupler, 30 W 1J503S Anaren L1, L2 Ferroxcube bead 2743019447 Fair Rite C1, C2, C4 100 nF ceramic 0805 S0805W104K1HRN-P4 MultiComp C3 4.7 μF C4532X7R1H475M TDK C5 1 μF C3216X7R1H105K TDK C6, C7, C19 15 pF 600F American Technical Ceramics C8 12 pF 600F American Technical Ceramics C13, C14 15 pF ATC100B150JT500X American Technical Ceramics C9, C10, C11, C12 1 μF GRM31CR72A105KA01L MuRata C15, C16 10 μF GRM32DF51H106ZA01L MuRata C20 220 μF, 50 V electrolytic SMT PCE3474CT-ND Panasonic C17 1.5 pF 600F American Technical Ceramics C18 1.8 pF 600F American Technical Ceramics AN10885_2 Application note All information provided in this document is subject to legal disclaimers. Rev. 02 — 25 February 2010 © NXP B.V. 2010. All rights reserved. 12 of 15 AN10885 NXP Semiconductors Doherty RF performance analysis using the BLF7G22LS-130 5. Abbreviations Table 3. Abbreviations Acronym Description ACPR Adjacent Channel Power Ratio CCDF Complementary Cumulative Distribution Function DPD Digital PreDistortion LDMOS Laterally Diffused Metal-Oxide Semiconductor PAR Peak-to-Average power Ratio SMT Surface-Mount Technology UMTS Universal Mobile Telecommunications System W-CDMA Wideband Code Division Multiple Access 6. References [1] AN10885_2 Application note Data sheet 1.3000; RO3000 Series High Frequency Circuit Materials − Advanced Circuit Materials Division; Rogers Corporation. All information provided in this document is subject to legal disclaimers. Rev. 02 — 25 February 2010 © NXP B.V. 2010. All rights reserved. 13 of 15 AN10885 NXP Semiconductors Doherty RF performance analysis using the BLF7G22LS-130 7. Legal information 7.1 Definitions Draft — The document is a draft version only. The content is still under internal review and subject to formal approval, which may result in modifications or additions. NXP Semiconductors does not give any representations or warranties as to the accuracy or completeness of information included herein and shall have no liability for the consequences of use of such information. 7.2 Applications — Applications that are described herein for any of these products are for illustrative purposes only. NXP Semiconductors makes no representation or warranty that such applications will be suitable for the specified use without further testing or modification. Disclaimers Limited warranty and liability — Information in this document is believed to be accurate and reliable. However, NXP Semiconductors does not give any representations or warranties, expressed or implied, as to the accuracy or completeness of such information and shall have no liability for the consequences of use of such information. In no event shall NXP Semiconductors be liable for any indirect, incidental, punitive, special or consequential damages (including - without limitation - lost profits, lost savings, business interruption, costs related to the removal or replacement of any products or rework charges) whether or not such damages are based on tort (including negligence), warranty, breach of contract or any other legal theory. Notwithstanding any damages that customer might incur for any reason whatsoever, NXP Semiconductors’ aggregate and cumulative liability towards customer for the products described herein shall be limited in accordance with the Terms and conditions of commercial sale of NXP Semiconductors. Right to make changes — NXP Semiconductors reserves the right to make changes to information published in this document, including without limitation specifications and product descriptions, at any time and without notice. This document supersedes and replaces all information supplied prior to the publication hereof. AN10885_2 Application note Suitability for use — NXP Semiconductors products are not designed, authorized or warranted to be suitable for use in medical, military, aircraft, space or life support equipment, nor in applications where failure or malfunction of an NXP Semiconductors product can reasonably be expected to result in personal injury, death or severe property or environmental damage. NXP Semiconductors accepts no liability for inclusion and/or use of NXP Semiconductors products in such equipment or applications and therefore such inclusion and/or use is at the customer’s own risk. NXP Semiconductors does not accept any liability related to any default, damage, costs or problem which is based on a weakness or default in the customer application/use or the application/use of customer’s third party customer(s) (hereinafter both referred to as “Application”). It is customer’s sole responsibility to check whether the NXP Semiconductors product is suitable and fit for the Application planned. Customer has to do all necessary testing for the Application in order to avoid a default of the Application and the product. NXP Semiconductors does not accept any liability in this respect. Export control — This document as well as the item(s) described herein may be subject to export control regulations. Export might require a prior authorization from national authorities. 7.3 Trademarks Notice: All referenced brands, product names, service names and trademarks are the property of their respective owners. All information provided in this document is subject to legal disclaimers. Rev. 02 — 25 February 2010 © NXP B.V. 2010. All rights reserved. 14 of 15 AN10885 NXP Semiconductors Doherty RF performance analysis using the BLF7G22LS-130 8. Contents 1 2 3 3.1 3.2 3.3 3.4 3.5 4 4.1 5 6 7 7.1 7.2 7.3 8 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 Test summary. . . . . . . . . . . . . . . . . . . . . . . . . . . 3 RF performance . . . . . . . . . . . . . . . . . . . . . . . . . 4 Network analyzer measurements . . . . . . . . . . . 4 IS-95 measurements . . . . . . . . . . . . . . . . . . . . 5 2-carrier W-CDMA measurements . . . . . . . . . . 6 Peak output power measurements . . . . . . . . . . 7 DPD measurements . . . . . . . . . . . . . . . . . . . . . 8 BLF7G22LS-130 Doherty test circuit . . . . . . . 11 BLF7G22LS-130 Doherty test circuit components . . . . . . . . . . . . . . . . . . . . . . . . . . 12 Abbreviations . . . . . . . . . . . . . . . . . . . . . . . . . . 13 References . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 Legal information. . . . . . . . . . . . . . . . . . . . . . . 14 Definitions . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 Disclaimers . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 Trademarks. . . . . . . . . . . . . . . . . . . . . . . . . . . 14 Contents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 Please be aware that important notices concerning this document and the product(s) described herein, have been included in section ‘Legal information’. © NXP B.V. 2010. All rights reserved. For more information, please visit: http://www.nxp.com For sales office addresses, please send an email to: [email protected] Date of release: 25 February 2010 Document identifier: AN10885_2