Design Application Note -- AN-044 SGA-8343 Amplifier Application Circuits Abstract RFMD SGA-8343 is a high performance SiGe amplifier designed for operation from DC to 6 GHz. This application note illustrates several application circuits for key frequency bands in the 800-2500 MHz spectrum. Introduction The application circuits were designed to achieve the optimum combination of NF, input return loss, and stability. All recommended components are standard values available from well-known manufacturers. Components specified in the bill of materials (BOM) have known parasitics which in some cases are critical to the circuit’s performance. Deviating from the recommended BOM may result in a performance shift due to varying parasitics. Matching component placement is critical to each circuit’s performance. active bias circuit or resistive feedback, the decreasing VBE will result in increased base and collector currents. As the collector current continues to increase under constant VCE conditions, the device may eventually exceed its maximum dissipated power limit resulting in permanent device damage. The designs included in this application note contain passive bias circuits that stabilize the device current over temperature and desensitize the circuit to device process variation. The passive bias circuits used in these designs include a dropping resistor in the collector bias line and a voltage divider from the collector-to-base. Using this scheme, the amplifier can be biased from a single supply voltage. The collector dropping resistor is sized to drop >20% VCE, depending on the desired VCE. The voltage divider from collector-to-base, in conjunction with the dropping resistor, will stabilize Circuit Details the device current over temperature. The effectiveRFMD will provide the detailed layout (AutoCAD forness increases with increasing voltage drop in collecmat) to users wishing to use the exact same layout tor bias line. Configuring the voltage divider such that and PCB material shown in the following circuits. The the shunt current is 5-10 times larger than the desired circuits recommended within this application note base current desensitizes the circuit to beta variation. were designed using the following PCB stack up: These two feedback mechanisms are sufficient to Material: GETEKTM ML 200C insure consistent performance over temperature and Core thickness: 0.031” device process variations. Note that the voltage drop Copper cladding: 1 oz. both sides is clearly dependent on the nominal collector current Dielectric constant: 4.1 and can be adjusted to generate the desired VCE Dielectric loss tangent: 0.0089 (@ 1 GHz) from a fixed supply rail. The user should test the cirCustomers not wishing to use the exact material and cuit over the operational extremes to guarantee adelayouts shown in this application note can design their quate performance. An active bias circuit can be own PCB using the critical transmission line impedimplemented if the user does not wish to sacrifice the ances and phase lengths shown in the BOMs and voltage required by the aforementioned passive cirlayouts. cuit. There are various active bias schemes suitable for HBTs. The user should choose an active bias cirNOTE: Many of our sample evaluation boards may cuit that best meets his/her cost, complexity, and percome with an additional substrate & copper layer for formance requirements. mechanical stability. It has been assumed that the backside layer has no effect on the RF performance Application Circuits Now Available or circuit design. 1. 800-1000 MHz, single-ended with series feedback, optimized for NF and S11< -10 dB. Design Considerations and Trade-offs 2. 1800-2000 MHz, single-ended, optimized for NF - Biasing Techniques and S11< -8 dB. All HBT amplifiers are subject to device current varia- 3. 2400-2500 MHz, single-ended, optimized for NF tion due to the decreasing nature of the internal VB E and S11< -10 dB. with increasing temperature. In the absence of an 4. 1575 MHz, GPS Application Circuits: see AN-061. The information provided herein is believed to be reliable at press time. RFMD assumes no responsibility for ina ccuracies or ommisions.RFMD assumes no responsibility for the use of this information, and all such information shall be entirely at the user’s own risk. Prices and specifications are subject to change without notice. No patent rights or licenses to any of the circuits described herein are implied or granted to any third party. RFMD does not authorize or warrant anyRFMD product for use in life-support devices and/or systems. Copyright 2003 RFMD. All worldwide rights reserved. 303 Technology Court, Broomfield, CO 80021 Phone: (800) SMI-MMIC 1 http://www.RFMD.com EAN-101847 Rev A Design Application Note -- AN-044 SGA-8343 Amplifier Application Circuits Vcc + VDROP - Ic IB + VCE - ISHUNT Passive Bias Circuit Topology Vs 6 R4 Q1a 2 1 C4 R3 R2 R1 R5 5 3 Q1b 4 C3 R6 C5 C6 L2 L1 SGA-8343 Active Bias Circuit Topology 303 Technology Court, Broomfield, CO 80021 Phone: (800) SMI-MMIC 2 http://www.RFMD.com EAN-101847 Rev A Design Application Note -- AN-044 SGA-8343 Amplifier Application Circuits 800-1000 MHz Application Circuit (VS =5V, ICQ =12mA) GND Vs=+5V (12mA) 160 Ω Copper Tape 2.4KΩ 910Ω 0.1uF 0.1uF 39pF 5.1Ω 39pF 0.1uF 18nH 2.4K Ω 39pF 120nH 6.8nH 39pF 0.5pF Copper Tape ECB-101766-B SOT-343 - FB Ref. Des. Part Number Value Ref. Des. Part Number Value C1, 2, 6, 8 ROHM MCH185A390J 39 pF R5 ROHM MCR03J161 160 Ω C7 ROHM MCH185A0R5C 0.5 pF Z1 non-critical 50 Ω C3, 4, 5 Samsung CL10B104KONC 0.1 uF Z2 4.0 degrees @ 900 MHz 50 Ω L1 TOKO LL1608-FS18NJ 18 nH Z3 11.5 degrees @ 900 MHz 63 Ω L2 TOKO LL1608-FSR12J 120 nH Z4 5.0 degrees @ 900 MHz 50 Ω L3 TOKO LL1608-FS6N8J 6.8 nH Z5 3.6 degrees @ 900 MHz 50 Ω R1 ROHM MCR03J5R1 5.1 Ω Z6 3.7 degrees @ 900 MHz 50 Ω R2 ROHM MCR03J911 910 Ω Z7 7.1 degrees @ 900 MHz 50 Ω R3, 4 ROHM MCR03J242 2.4K Ω Z8 non-critical 50 Ω SGA-8343 800-1000 MHz Schematic R5 R3 Vs=5V C4 R2 C3 C6 R1 C5 Z3 L2 R4 C2 L1 Z1 C8 L3 Z5 C1 Z2 SGA-8343 Z6 Z7 Z8 C7 Z4 303 Technology Court, Broomfield, CO 80021 Phone: (800) SMI-MMIC 3 http://www.RFMD.com EAN-101847 Rev A Design Application Note -- AN-044 SGA-8343 Amplifier Application Circuits Typical Performance: 800-1000 MHz Application Circuit (VS=5V, I CQ =12mA, 25C) Gain vs. Freq 20 18 1.8 16 1.6 dB dB NF vs. Frequency 2 14 1.4 12 1.2 10 0.8 0.85 0.9 0.95 1 1 0.8 GHz 0.9 GHz 0.95 1 0.95 1 P1dB vs. Frequency 10 30 8 28 6 dBm dBm Third Order Intercept vs. Frequency (Pout per tone = 0dBm) 0.85 26 24 4 2 22 0 20 0.8 0.85 0.9 0.95 0.8 1 0.85 0.9 GHz GHz Input/Output Return Loss, Isolation vs. Frequency 0 S11 S12 S22 -5 dB -10 -15 -20 -25 0.8 0.85 0.9 GHz 0.95 1 Freq (GHz) P1dB (dBm) OIP3 (dBm) Gain (dB) S11 (dB) S22 (dB) NF (dB) 0.800 8.8 27.0 19.1 -20 -16 1.20 0.900 9.0 27.3 18.2 -16 -18 1.25 1.000 9.0 27.5 17.3 -14 -16 1.20 303 Technology Court, Broomfield, CO 80021 Phone: (800) SMI-MMIC 4 http://www.RFMD.com EAN-101847 Rev A Design Application Note -- AN-044 SGA-8343 Amplifier Application Circuits 1800-2000 MHz Application Circuit (VS =5V, ICQ =12mA) Vs=+5V (12mA) GND 160Ω 2.4KΩ 910Ω 0.1uF 0.1uF 10pF 5.1Ω 5.1Ω 2.2pF 39pF 10pF 18nH 3.3nH 3.9nH 39pF Critical Cut Copper Tape ECB-101765-F SOT-343 - SERIES FB Ref. Des. Part Number Value Ref. Des. Part Number Value C1, 7 ROHM MCH185A390J 39 pF R4 ROHM MCR03J161 160 Ω C2 ROHM MCH185A2R2C 2.2 pF Z1 non-critical 50 Ω C3, 6 ROHM MCH185A100D 10 pF Z2 3.9 degrees @ 1900 MHz 50 Ω C4, 5 Samsung CL10B104KONC 0.1uF Z3 4.7 degrees @ 1900 MHz 50 Ω L1 TOKO LL1608-FS3N9S 3.9 nH Z4 6.4 degrees @ 1900 MHz 50 Ω L2 TOKO LL1608-FS18NJ 18 nH Z5 9.8 degrees @ 1900 MHz 50 Ω L3 TOKO LL1608-FS3N3S 3.3 nH Z6 9.8 degrees @ 1900 MHz 50 Ω R1, 5 ROHM MCR03J5R1 5.1 Ω Z7 28.7 degrees @ 1900 MHz 50 Ω R2 ROHM MCR03J911 910 Ω Z8 non-critical 50 Ω R3 ROHM MCR03J242 2.4K Ω SGA-8343 1800-2000 MHz Schematic R4 R3 C4 R2 Vs=5V C5 R5 R1 C6 L3 C3 C7 L2 C1 SGA-8343 C2 Z1 Z2 Z3 Z7 Z8 Z4 L1 Phone: (800) SMI-MMIC 5 Z6 Z5 303 Technology Court, Broomfield, CO 80021 http://www.RFMD.com EAN-101847 Rev A Design Application Note -- AN-044 SGA-8343 Amplifier Application Circuits Typical Performance: 1800-2000 MHz Application Circuit (V S=5V, I CQ=12mA) NF vs. Frequency (25C) 20 2 18 1.8 16 1.6 dBm dB Gain vs. Frequency 25C 85C -40C 14 12 1.4 1.2 1 10 1.8 1.85 1.9 GHz 1.95 2 1.8 Third Order Intercept vs. Frequency (Pout per tone = 0dBm) 1.9 GHz 1.95 2 P1dB vs. Frequency 15 30 13 26 dBm 28 dBm 1.85 25C 24 85C 22 20 1.85 9 25C 85C 7 -40C 1.8 11 1.9 GHz 1.95 -40C 5 2 1.8 1.85 1.9 GHz 1.95 2 Input/Output Return Loss, Isolation vs. Frequency 0 -5 dB -10 -15 -20 S11 S22 S12 -25 -30 1.8 1.85 1.9 GHz 1.95 2 Freq (GHz) P1dB (dBm) OIP3 (dBm) Gain (dB) S11 (dB) S22 (dB) NF (dB) 1.8 9.8 27.5 17.0 -10 -26 1.40 1.9 10.0 27.8 16.5 -9 -24 1.40 2.0 10.5 27.7 15.6 -8 -17 1.45 303 Technology Court, Broomfield, CO 80021 Phone: (800) SMI-MMIC 6 http://www.RFMD.com EAN-101847 Rev A Design Application Note -- AN-044 SGA-8343 Amplifier Application Circuits 2400-2500 MHz Application Circuit (VS=3.3V, ICQ=10mA) GND Vs=+3.3V (10mA) 62Ω 2.2KΩ 1K Ω 0.1uF 5.6pF 10Ω 1.0pF 5.6pF 0.1uF 10Ω 5.6pF 2.7nH 10nH 5.6pF Copper Tape ECB-101766-B SOT-343 - FB Ref. Des. Part Number Value Ref. Des. Part Number Value C1, 3, 6, 7 ROHM MCH185A5R6D 5.6 pF R5 ROHM MCR50J620 62 Ω C2 ROHM MCH185A010C 1.0 pF Z1 non-critical 50 Ω C4, 5 Samsung CL10B104KONC 0.1uF Z2 8.2 degrees @ 2440 MHz 50 Ω L1 TOKO LL1608-FS10NJ 10 nH Z3 21.7 degrees @ 2440 MHz 50 Ω L2 TOKO LL1608-FS2N7S 2.7 nH Z4 6.2 degrees @ 2440 MHz 50 Ω R1, 4 ROHM MCR03J100 10 Ω Z5 6.2 degrees @ 2440 MHz 50 Ω R2 ROHM MCR03J102 1K Ω Z6 23.8 degrees @ 2440 MHz 50 Ω R3 ROHM MCR03J222 2.2K Ω Z7 non-critical 50 Ω SGA-8343 2400-2500 MHz Schematic R5 R3 Vs=3.3V C5 R2 C4 R4 R1 C6 L2 C3 C7 L1 Z6 C1 Z1 Z2 Z3 Z7 SGA-8343 C2 Z4 303 Technology Court, Broomfield, CO 80021 Z5 Phone: (800) SMI-MMIC 7 http://www.RFMD.com EAN-101847 Rev A Design Application Note -- AN-044 SGA-8343 Amplifier Application Circuits Typical Performance: 2400-2500 MHz Application Circuit (V S=3.3 V, I CQ=10mA, 25C) Gain vs. Frequency NF vs. Frequency 20 2 1.8 16 dB dB 18 14 1.6 1.4 12 1.2 10 2.4 2.42 2.44 2.46 2.48 1 2.5 2.4 GHz 2.44 2.46 2.48 2.5 2.48 2.5 GHz P1dB vs. Frequency Third Order Intercept vs. Frequency (Pout per tone = 0dBm) 15 30 13 dBm 28 dBm 2.42 26 24 11 9 22 7 20 5 2.4 2.42 2.44 2.46 2.48 2.4 2.5 2.42 2.44 2.46 GHz GHz Input/Output Return Loss, Isolation vs. Frequency 0 S11 S12 S22 -5 dB -10 -15 -20 -25 -30 2.4 2.42 2.44 GHz 2.46 2.48 2.5 Freq (GHz) P1dB (dBm) OIP3 (dBm) Gain (dB) S11 (dB) S22 (dB) NF (dB) 2.40 9.0 27.5 14.6 -12 -24 1.50 2.45 9.2 27.5 14.4 -13 -24 1.60 2.50 9.4 27.5 14.2 -14 -23 1.65 303 Technology Court, Broomfield, CO 80021 Phone: (800) SMI-MMIC 8 http://www.RFMD.com EAN-101847 Rev A