A pp li c at io n N o t e, R e v . 1. 2 , N ov e m be r 2 00 7 A p p li c a t i o n N o t e N o . 1 3 1 A Lo w C o s t , T w o S ta g e L N A f o r 5 t o 6 G H z " 8 0 2 . 1 1a " A pp l i c a t i o n s u s i n g t h e S i G e B F P 6 4 0 R F & P r o t e c ti o n D e v i c e s Edition 2007-11-27 Published by Infineon Technologies AG 81726 München, Germany © Infineon Technologies AG 2009. 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. Application Note No. 131 Application Note No. 131 Revision History: 2007-11-27, Rev. 1.2 Previous Version: 2002-11-16, Rev. 1.1 Page Subjects (major changes since last revision) All Small changes in figure descriptions Application Note 3 Rev. 1.2, 2007-11-27 Application Note No. 131 A Low Cost, Two Stage LNA for 5 to 6 GHz "802.11a" Applications using the 1 A Low Cost, Two Stage LNA for 5 to 6 GHz "802.11a" Applications using the SiGe BFP640 Overview • • • • • The Silicon-Germanium BFP640 is evaluated on a PCB to show the feasibility of a very low-cost, discrete TwoStage LNA design in the 5 - 6 GHz range. The Printed Circuit Board Used is PCB 640-052402 Revision A. Standard FR4 material is used. Note that the PCB allows for the tune / test of each stage separately, prior to integrating the two stages. This is achieved with a third SMA RF connector positioned between the two stages. Low-cost, standard SMT passive components are used Total PCB area used for both stages is approximately 100 mm². Note that further reduction in PCB area is possible. Achieved > 20 dB gain, 1.4 dB Noise Figure at 5450 MHz, on 3.3 V supply, drawing 15.9 mA. Note noise figure result does NOT "back out" FR4 PCB losses - if the PCB loss at LNA input were extracted, Noise Figure Results would be approximately 0.3 dB lower. PCB Cross - Section Diagram 7+,663$&,1*&5,7,&$/ 723/$<(5 LQFKPP ,17(51$/*5281'3/$1( LQFKPP" /$<(5)250(&+$1,&$/5,*,',7<2)3&%7+,&.1(66+(5(127&5,7,&$/$6 /21*$6727$/3&%7+,&.1(66'2(6127(;&((',1&+PP 63(&,),&$7,21)25727$/3&%7+,&.1(66,1&+ PPPP %27720/$<(5 $1B3&%YVG Figure 1 PCB - Cross Sectional Diagram Application Note 4 Rev. 1.2, 2007-11-27 Application Note No. 131 A Low Cost, Two Stage LNA for 5 to 6 GHz "802.11a" Applications using the Summary of Data for Two-Stage Cascade T = 25 °C, network analyzer source power = -35 dBm Table 1 Summary of Data for Two-Stage Cascade Parameter Result Comments Frequency Range 5 - 6 GHz Various portions of this range are usable on a worldwide basis for 802.11b, HiperLAN DC Current 15.9 mA Low current consumption DC Voltage, VCC 3.3 V Collector-Emitter Voltage, VCE ≅ 2.9 V, each stage BFP640 BVCEO of 4.0 V would permit higher voltage operation. Higher bias voltage would improve linearity and slightly increase gain Gain 22.7 dB @ 5150 MHz 22.4 dB @ 5250 MHz 22.1 dB @ 5350 MHz 21.6 dB @ 5470 MHz 20.2 dB @ 5825 MHz Cascade Noise Figure 1.4 dB @ 5150 MHz 1.4 dB @ 5250 MHz 1.4 dB @ 5350 MHz 1.4 dB @ 5470 MHz 1.5 dB @ 5825 MHz Input P1dB -14.7 dBm @ 5350 MHz See input power sweep vs. gain plot, Figure 6. Input 3 Order Intercept +4.6 dBm @ 5350 MHz Please see plots Figure 13 & Figure 14 Input Return Loss 12.2 dB @ 5150 MHz 13.3 dB @ 5250 MHz 14.5 dB @ 5350 MHz 16.0 dB @ 5470 MHz 19.9 dB @ 5825 MHz Good broadband input match Output Return Loss 9.7 dB @ 5150 MHz 10.5 dB @ 5250 MHz 12.2 dB @ 5350 MHz 13.8 dB @ 5470 MHz 19.9 dB @ 5825 MHz Good broadband output match Reverse Isolation 34.9 dB @ 5150 MHz 34.0 dB @ 5250 MHz 34.5 dB @ 5350 MHz 34.7 dB @ 5470 MHz 33.7 dB @ 5825 MHz rd Application Note 5 Rev. 1.2, 2007-11-27 Application Note No. 131 A Low Cost, Two Stage LNA for 5 to 6 GHz "802.11a" Applications using the Bill of Material Table 2 Bill of Material, Complete Two-Stage Cascade Reference Designator Value Manufacturer Case Size Function C1, C2, C7 1.5 pF Various 0402 DC blocking C4. C5, C9, C10 1.5 pF Various 0402 RF bypass / RF block C3, C6, C8, C11 0.033 µF Various 0402 Low frequency ground at base (input ThirdOrder Intercept improvement), low frequency decoupling / blocking L1, L4 6.2 nH Murata LQP15M tight tolerance inductor (former Murata part number = LQP10A) 0402 RF choke to DC bias on base of Q1 and Q2 L2, L5 5.6 nH Murata LQP15M tight tolerance inductor 0402 RF choke to collector of Q1 and Q2; also influences output match of each stage L3 1.3 nH Murata LQP15M tight tolerance inductor 0402 Output matching, stage 1 L6 1.5 nH Murata LQP15M tight tolerance inductor 0402 Output matching, stage 2 R1, R4 10 Ω Various 0402 For stability, output matching R2, r5 43 kΩ Various 0402 DC bias for base of Q1 and Q2 R3, R6 30 Ω Various 0402 Drop supply voltage by approx. 0.3 V, provide DC feedback for bias compensation (beta variation, temperature, etc.) Q1, Q2 - Infineon Technologies SOT-343 BFP640F SiGe Transistor, fT = 36 GHz J1, J2, J3 - Johnson 142-0701-841 - RF input / output connectors (J2 only used when testing stages individually) J4 - AMP 5 pin header MTA100 series 640456-5 (standard pin plating) or 641215-5 (gold plated pins) - DC connector Application Note Pins 1, 5 = ground Pin 3 = VCC Pins 2, 4 = no connection 6 Rev. 1.2, 2007-11-27 Application Note No. 131 A Low Cost, Two Stage LNA for 5 to 6 GHz "802.11a" Applications using the Schematic Diagram, Two-Stage Cascade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igure 2 Schematic Diagram Application Note 7 Rev. 1.2, 2007-11-27 Application Note No. 131 A Low Cost, Two Stage LNA for 5 to 6 GHz "802.11a" Applications using the Noise Figure, Plot, Two-Stage Cascade, Center of Plot (x-axis) is 5500 MHz. 5RKGHDQG6FKZDU])6(.9 1RY %)31RLVH)LJXUH (871DPH 0DQXIDFWXUHU 2SHUDWLQJ&RQGLWLRQV 2SHUDWRU1DPH 7HVW6SHFLILFDWLRQ &RPPHQW 7ZR6WDJH/1$PLW%)3 ,QILQHRQ 9 9, P$7 & *HUDUG:HYHUV *+]/1$ /:56'/1$3 1RY $QDO\]HU 5)$WW 5HI/YO G% G%P 5%: 9%: 0+] +] 5DQJH G% 5HI/YODXWR 21 0RGH 'LUHFW (15 +3% 0HDVXUHPHQW QGVWDJHFRUU 21 1RLVH)LJXUHG% 0+] 0+]',9 0+] $1BSORWBQIYVG Figure 3 Noise Figure Application Note 8 Rev. 1.2, 2007-11-27 Application Note No. 131 A Low Cost, Two Stage LNA for 5 to 6 GHz "802.11a" Applications using the Noise Figure, Tabular Data, Two-Stage From Rohde & Schwarz SFEK3 + FSEB30 System Preamplifier = MITEQ AFS3-04000800-10-ULN Table 3 Noise Figure Frequency Noise Figure 5000 MHz 1.32 dB 5025 MHz 1.34 dB 5050 MHz 1.35 dB 5075 MHz 1.34 dB 5100 MHz 1.36 dB 5125 MHz 1.36 dB 5150 MHz 1.36 dB 5175 MHz 1.37 dB 5200 MHz 1.37 dB 5225 MHz 1.35 dB 5250 MHz 1.38 dB 5275 MHz 1.39 dB 5300 MHz 1.37 dB 5325 MHz 1.37 dB 5350 MHz 1.39 dB 5375 MHz 1.40 dB 5400 MHz 1.39 dB 5425 MHz 1.44 dB 5450 MHz 1.44 dB 5475 MHz 1.41 dB 5500 MHz 1.45 dB 5525 MHz 1.46 dB 5550 MHz 1.47 dB 5575 MHz 1.48 dB 5600 MHz 1.50 dB 5625 MHz 1.49 dB 5650 MHz 1.52 dB 5675 MHz 1.53 dB 5700 MHz 1.51 dB 5725 MHz 1.54 dB 5750 MHz 0.56 dB 5775 MHz 1.55 dB 5800 MHz 1.54 dB 5825 MHz 1.53 dB 5850 MHz 1.55 dB 5875 MHz 1.55 dB 5900 MHz 1.57 dB Application Note 9 Rev. 1.2, 2007-11-27 Application Note No. 131 A Low Cost, Two Stage LNA for 5 to 6 GHz "802.11a" Applications using the Table 3 Noise Figure (cont’d) Frequency Noise Figure 5925 MHz 1.56 dB 5950 MHz 1.55 dB 5975 MHz 1.56 dB 6000 MHz 1.54 dB Application Note 10 Rev. 1.2, 2007-11-27 Application Note No. 131 A Low Cost, Two Stage LNA for 5 to 6 GHz "802.11a" Applications using the Scanned Image of PC Board, Two-Stage Cascade By swinging a capacitor tacked to the output of Stage 1 down or to the right, the individual stages may be tested alone prior to integration. To test Stage 1 by itself, signal flow is from leftmost RF connector (input) to bottom RF connector [output]; to test Stage 2 alone, signal flow is from bottom RF connector [input] to rightmost RF connector [output]. The DC block between stages, C2, can be swung from output of Stage 1 down to lower RF connector to test Stage 1 alone; likewise C2 can be swung from track leading to lower RF connector up to right at a 45 degree angle to connect to input of Stage 2, to test Stage 2 alone. Figure 4 Image of PC Board Application Note 11 Rev. 1.2, 2007-11-27 Application Note No. 131 A Low Cost, Two Stage LNA for 5 to 6 GHz "802.11a" Applications using the Scanned Image of PC Board, Two-Stage Cascade, Close-In Shot Figure 5 Image of PC Board, Close-In Shot Application Note 12 Rev. 1.2, 2007-11-27 Application Note No. 131 A Low Cost, Two Stage LNA for 5 to 6 GHz "802.11a" Applications using the Power Sweep at 5350 MHz (CW) Source Power (Input) swept from -25 to 0 dBm Input P1dB ≅ -15.7 dBm &+ 6 ORJ0$* G% 5()G% 1RY BG% G%P 35P BG% G%P &RU 'HO 6PR 67$57G%P &:0+] 6723G%P $1BSORWBSRZHUBVZHHSYVG Figure 6 Plot of Power Sweep at 5350 MHz Application Note 13 Rev. 1.2, 2007-11-27 Application Note No. 131 A Low Cost, Two Stage LNA for 5 to 6 GHz "802.11a" Applications using the Input Return Loss, Log Mag Cascade, 2 Stages &+ 6 ORJ0$* G% 5()G% 1RY BG% 0+] 35P BG% *+] &RU BG% *+] 'HO BG% *+] BG% *+] 67$570+] 67230+] $1BSORWBLQSXWBUHWXUQBORVVYVG Figure 7 Plot of Input Return Loss Application Note 14 Rev. 1.2, 2007-11-27 Application Note No. 131 A Low Cost, Two Stage LNA for 5 to 6 GHz "802.11a" Applications using the Input Return Loss, Smith Chart Cascade, 2 Stages Reference Plane = PCB Input SMA Connector &+ 6 8)6 1RY S) B 0+] 35P B *+] &RU B *+] 'HO B *+] B *+] 67$570+] 67230+] $1BVPLWKBLQSXWBUHWXUQBORVVYVG Figure 8 Smith Chart of Input Return Loss Application Note 15 Rev. 1.2, 2007-11-27 Application Note No. 131 A Low Cost, Two Stage LNA for 5 to 6 GHz "802.11a" Applications using the Forward Gain Cascade, 2 Stages &+ 6 ORJ0$* G% 5()G% 1RY BG% 0+] 35P &RU 'HO BG% *+] 5()(5(1&(/,1(326,7,21 'LY BG% *+] BG% *+] BG% *+] 67$570+] 67230+] $1BSORWBIZBJDLQYVG Figure 9 Plot of Forward Gain Application Note 16 Rev. 1.2, 2007-11-27 Application Note No. 131 A Low Cost, Two Stage LNA for 5 to 6 GHz "802.11a" Applications using the Reverse Isolation Cascade, 2 Stages &+ 6 ORJ0$* G% 5()G% 1RY BG% 0+] 35P BG% *+] &RU BG% *+] 'HO BG% *+] BG% *+] 67$570+] 67230+] $1BSORWBUHYHUVHBLVRODWLRQYVG Figure 10 Plot of Reverse Isolation Application Note 17 Rev. 1.2, 2007-11-27 Application Note No. 131 A Low Cost, Two Stage LNA for 5 to 6 GHz "802.11a" Applications using the Output Return Loss, Log Mag Cascade, 2 Stages &+ 6 ORJ0$* G% 5()G% 1RY BG% 0+] 35P &RU 'HO BG% *+] 6&$/( G%GLY BG% *+] BG% *+] BG% *+] 67$570+] 67230+] $1BSORWBRXWSXWBUHWXUQBORVVYVG Figure 11 Plot of Output Return Loss Application Note 18 Rev. 1.2, 2007-11-27 Application Note No. 131 A Low Cost, Two Stage LNA for 5 to 6 GHz "802.11a" Applications using the Output Return Loss, Smith Chart Cascade, 2 Stages Reference Plane = PCB Output SMA Connector &+ 6 8)6 1RY S+ B 0+] 35P B *+] &RU B *+] 'HO B *+] B *+] 67$570+] 67230+] $1BVPLWKBRXWSXWBUHWXUQBORVVYVG Figure 12 Smith Chart of Output Return Loss Application Note 19 Rev. 1.2, 2007-11-27 Application Note No. 131 A Low Cost, Two Stage LNA for 5 to 6 GHz "802.11a" Applications using the Two-Tone Third Order Intercept Test, 5350 MHz Input Stimulus for Two-Tone Third Order Intercept Test. f1 = 5349 MHz, f2 = 5350 MHz, -23 dBm each tone. $1BSORWBWZRBWRQHBLQSXWYVG Figure 13 Tow-Tone Test, Input Stimulus @ 5350 MHz Application Note 20 Rev. 1.2, 2007-11-27 Application Note No. 131 A Low Cost, Two Stage LNA for 5 to 6 GHz "802.11a" Applications using the Two-Tone Third Order Intercept Test, 5350 MHz LNA Output Response to Two-Tone Test. Input 3rd Order Intercept = -23 + (55.2 / 2) = +4.6 dBm $1BSORWBWZRBWRQHBUHVSRQVHYVG Figure 14 Tow-Tone Test, LNA Response @ 5350 MHz Application Note 21 Rev. 1.2, 2007-11-27