AN-079 SGA-8543Z ML200C EAN-104851 MCH182CN104K MCH185A221JK MCH185A680JK

SGA-8543Z Amplifier Application Circuits Design Considerations and Trade-offs -Biasing Techniques Abstract Sirenza Microdevices'

Design Application Note - AN-079 AN-079 SGA-8543Z SGA-8543Z Amplifier Application Circuits Design Considerations and Trade-offs -Biasing Techniques Abstract Sirenza Microdevices' SGA-8543Z SGA-8543Z is a high performance SiGe amplifier designed for operation from 50 MHz to 3.5 GHz. This application note illustrates application circuits for the 880 MHz and 2440 MHz frequency bands. Introduction The application circuits were designed to achieve the optimum combination of NF, P1dB, and OIP3, while maintaining flat gain and reasonable return losses. Special consideration was given to insure amplifier stability at low frequencies, where the device exhibits high gain. These designs were created to illustrate the general performance capabilities of the device under CW conditions. Users may wish to modify these designs to achieve optimum performance under specific input conditions and system requirements. 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. Circuit Details SMDI will provide the detailed layout (AutoCad format) to users wishing to use the exact same layout and substrate material shown in the following circuits. The circuits recommended within this application note were designed using the following PCB stackup: All HBT amplifiers are subject to device current variation due to the decreasing nature of the internal VBE with increasing temperature. In the absence of an 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 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 the device current over temperature. Configuring the voltage divider such that the shunt current is 5-10 times larger than the desired base current desensitizes the circuit to beta variation. These two feedback mechanisms are sufficient to insure consistent performance over temperature and device process variations. Note that the voltage drop is clearly dependent on the nominal collector current and can be adjusted to generate the desired VCE from a fixed supply rail. The user should test the circuit over the operational extremes to guarantee adequate performance if the feedback mechanisms are reduced. Vcc Material: GETEKTM ML200C ML200C Core thickness: 0.031" Copper cladding: 1 oz. both sides Dielectric constant: 4.1 Dielectric loss tangent: 0.0089 (@ 1 GHz) + VDROP Ic Customers not wishing to use the exact material and layouts shown in this application note can design their own PCB using the critical transmission line impedances and phase lengths shown in the BOMs and layouts. IB + VCE ISHUNT - The information provided herein is believed to be reliable at press time. Sirenza Microdevices assumes no responsibility for inaccuracies or omissions. Sirenza Microdevices 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. Sirenza Microdevices does not authorize or warrant any Sirenza Microdevices product for use in life-support devices and/or systems. Copyright 2005 Sirenza Microdevices, Inc. All worldwide rights reserved. 303 S. Technology Ct. Broomfield, CO 80021 Phone: (800) SMI-MMIC 1 http://www.sirenza.com EAN-104851 EAN-104851 Rev B Design Application Note - AN-079 AN-079 SGA-8543Z SGA-8543Z Amplifier Application Circuits Vs = 5V 880 MHz Application Circuit (Vs=5V, Is=96mA) 20, 1/4W 130 10 150 39pF 1.1 Note: Electrical lengths =50, 3.4° =50, 2.7° are determined from the center of a shunt component and a cut on the center trace 220pF 22nH 3.9nH 4.7nH 68pF =50, 13.1° 0.1uF =50, 3.3° 150 =50, 1.8° =50, 2.8° =50, 2.4° 3.9pF =50, 2.4° 68pF 5.6pF Bill of Materials C1 MCH182CN104K MCH182CN104K Rohm 0.1uF C2 MCH185A221JK MCH185A221JK Rohm 220pF C3 MCH185A680JK MCH185A680JK Rohm 68pF C4 MCH155A5R6DK MCH155A5R6DK Rohm 5.6pF (0402) C5 MCH185A390JK MCH185A390JK Rohm 39pF C6 MCH185A3R9CK MCH185A3R9CK Rohm 3.9pF C7 MCH185A680JK MCH185A680JK Rohm 68pF L1 LL1608-FS4N7S LL1608-FS4N7S Toko 4.7nH L2 LL1608-FS3N9S LL1608-FS3N9S Toko 3.9nH L3 LL1608-FS22NJ LL1608-FS22NJ Toko 22nH R1 20 1206, 1/4W res (5%) R2 150 0603 res (5%) R3 130 0603 res (5%) R4 10 0603 res (5%) R5 1.1K 0603 res (5%) R6 150 0402 res (5%) Connectors 2x PSF-S01-1mm GigaLane Co. Heat sink EEF-102059 EEF-102059 PCB SOT-343 Rev B 303 S. Technology Ct. Broomfield, CO 80021 Phone: (800) SMI-MMIC 2 http://www.sirenza.com EAN-104851 EAN-104851 Rev B Design Application Note - AN-079 AN-079 SGA-8543Z SGA-8543Z Amplifier Application Circuits 880 MHz Application Circuit Data, VS= 5V, IS= 96mA Noise Figure vs. Frequency Gain Vs. Frequency 5 25 4.5 23 25C -40C 85C 85C 21 Gain (dB) NF (dB) 4 3.5 3 25C 19 17 2.5 2 850 860 870 880 890 900 15 850 910 860 Frequency (MHz) 900 910 38 OIP3 (dBm) -10 -15 -20 dB 890 40 -5 -25 -30 S12 S22 36 34 32 25C S11 -35 -40 850 860 870 880 890 900 -40C 30 28 850 910 85C 860 Frequency (MHz) IM3/IM5 vs. Tone Power @880MHz 890 900 22 85C P1dB (dBm) IM3 -60 -70 -80 910 25C 21 -40C -50 880 P1dB vs. Frequency 22 25C -40 870 Frequency (MHz) -30 IM3/IM5 (dBm) 880 OIP3 vs. Freq. (5dBm Output Tones) Input/Output Return Loss, Isolation vs. Frequency, T=25C 0 870 Frequency (MHz) -40C 85C 21 20 20 19 IM5 -90 19 -100 -4 -2 0 2 4 6 8 10 12 18 850 Pout per tone (dBm) 303 S. Technology Ct. Broomfield, CO 80021 860 870 880 890 900 910 Frequency (MHz) Phone: (800) SMI-MMIC 3 http://www.sirenza.com EAN-104851 EAN-104851 Rev B Design Application Note - AN-079 AN-079 SGA-8543Z SGA-8543Z Amplifier Application Circuits Vs = 5V 2440 MHz Application Circuit (Vs=5V, Is=96mA) 20, 1/4W 130 .01uF 150 5.6pF Note: Electrical lengths 1.2 100 2.2pF =50, 6.7° =50, 7.9° 4.7pF =50, 7.6° are determined from the center of a shunt component and a cut on the center trace =50, 4° 15nH =50, 5.9° 1.5pF =50, 18.4° =50, 24.7° 1.8pF Bill of Materials C1 MCH182CN104K MCH182CN104K Rohm 0.1uF C2 MCH185A2R2CK MCH185A2R2CK Rohm 2.2pF C3 MCH185A4R7CK MCH185A4R7CK Rohm 4.7pF C4 MCH185A1R5CK MCH185A1R5CK Rohm 1.5pF C5 MCH185A5R6DK MCH185A5R6DK Rohm 5.6pF C6 MCH185A1R8CK MCH185A1R8CK Rohm 1.8pF L1 LL1608-FS15NJ LL1608-FS15NJ Toko 15nH R1 20 1206, 1/4W res (5%) R2 150 0603 res (5%) R3 130 0603 res (5%) R4 100 0603 res (5%) R5 1.2K 0603 res (5%) Connectors 2x PSF-S01-1mm GigaLane Co. Heat sink EEF-102059 EEF-102059 PCB SOT-343 Rev B 303 S. Technology Ct. Broomfield, CO 80021 Phone: (800) SMI-MMIC 4 http://www.sirenza.com EAN-104851 EAN-104851 Rev B Design Application Note - AN-079 AN-079 SGA-8543Z SGA-8543Z Amplifier Application Circuits 2440 MHz Application Circuit Data, VS= 5V, IS= 96mA Noise Figure vs. Frequency Gain Vs. Frequency 4 19 3.5 17 85C 25C -40C 85C 3 Gain (dB) NF (dB) 15 2.5 25C 2 13 11 1.5 1 2410 2420 2430 2440 2450 2460 9 2410 2470 2420 Frequency (MHz) 2460 2470 OIP3 vs. Freq. (5dBm Output Tones) 38 OIP3 (dBm) -10 -15 -20 dB 2450 40 -5 -25 -30 S12 S22 36 34 32 25C S11 -35 -40 2410 2420 2430 2440 2450 2460 -40C 30 28 2410 2470 85C 2420 Frequency (MHz) IM3 / IM5 vs. Tone Power @2440MHz 2450 IM3 85C P1dB (dBm) -70 IM5 -80 21 20 20 25C 19 -90 -40C 85C 19 -100 -2 0 2 4 6 8 10 12 18 2410 Pout per tone (dBm) 303 S. Technology Ct. Broomfield, CO 80021 2470 21 -60 -4 2460 22 -40C -50 2440 P1dB vs. Frequency 22 25C -40 2430 Frequency (MHz) -30 IM3/IM5 (dBm) 2440 Frequency (MHz) Input/Output Return Loss, Isolation vs. Frequency, T=25C 0 2430 2420 2430 2440 2450 2460 2470 Frequency (MHz) Phone: (800) SMI-MMIC 5 http://www.sirenza.com EAN-104851 EAN-104851 Rev B