A pp li c at i on N ot e , R ev . 2. 0 , N ov . 2 00 6 A p p li c a t i o n N o t e N o . 0 1 5 L o w - N o i s e- A m p l i f i e r o p t i m i z e d fo r m i n i m u m N o i s e F i g u r e a t 1 . 9 G H z u s i ng B F P 42 0 R F & P r o t e c ti o n D e v i c e s Edition 2006-11-14 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. INFINEON TECHNOLOGIES HEREBY DISCLAIMS ANY AND ALL WARRANTIES AND LIABILITIES OF ANY KIND (INCLUDING WITHOUT LIMITATION WARRANTIES OF NON-INFRINGEMENT OF INTELLECTUAL PROPERTY RIGHTS OF ANY THIRD PARTY) WITH RESPECT TO ANY AND ALL INFORMATION GIVEN IN THIS APPLICATION NOTE. Information For further information on technology, delivery terms and conditions and prices please contact your nearest Infineon Technologies Office (www.infineon.com). Warnings Due to technical requirements components may contain dangerous substances. For information on the types in question please contact your nearest Infineon Technologies Office. Infineon Technologies Components may only be used in life-support devices or systems with the express written approval of Infineon Technologies, if a failure of such components can reasonably be expected to cause the failure of that life-support device or system, or to affect the safety or effectiveness of that device or system. 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. 015 Low-Noise-Amplifier optimised for minimum Noise Figure at 1.9 GHz using BFP420 Revision History: 2006-11-14, Rev. 2.0 Previous Version: Page Subjects (major changes since last revision) All Document layout change Trademarks SIEGET® is a registered trademark of Infineon Technologies AG. Application Note 3 Rev. 2.0, 2006-11-14 Application Note No. 015 Low-Noise-Amplifier optimised for minimum Noise Figure at 1.9 GHz using 1 Low-Noise-Amplifier optimised for minimum Noise Figure at 1.9 GHz using BFP420 This application note provides general information, print layout and list of used components, circuit layout and measured data of a low noise amplifier at 1.9 GHz using SIEMENS SIEGET®25 BFP420. This circuit is optimised for low noise figure values. Data at 1.9 GHz (3 V and 5 mA) Gain: 13 dB IP3out: NF:: RLin: RLout: 10 dB 1.4 dB >7 dB >20 dB The amplifier application circuit has been optimised to achieve optimum noise figure and good stability at 1.9 GHz, combined with low operating current and voltage for use in handheld equipment. The transistor is matched using microstrip lines at input and output in conjunction with capacitors to ground. The added emitter inductance reduces gain but it provides the best overall matching conditions for maximum gain and minimum noise figure. The active bias controller BCR400W is used to provide bias stability over the operating temperature range. For additional information on this part please refer to application note No.014. The collector resistor is used for increase stability for the RF-transistor and omits the need to use λ/4 transmission lines for biasing. In order to avoid AF oscillations for the BCR400W, the blocking capacitor at the base of the RF transistor should be at least ten times the value used at collector. IC1 2 C5=4.7µF 1 BCR400W C4=1nF R3=150 Ohm C7=1nF C3=22pF C6=22pF R2=150 Ohm R1=10k RFin +3V 3 4 RFout TrL4 TrL1 C2=0.8pF C1=0.5pF Tr1=BFP420 TrL2 TrL3 AN015_application.vsd Figure 1 Schematic Diagram Application Note 4 Rev. 2.0, 2006-11-14 Application Note No. 015 Low-Noise-Amplifier optimised for minimum Noise Figure at 1.9 GHz using 25mm x 20mm 150 Ohm 4.7µF 0 Ohm BCR400W 1 nF 22 pF 1 nF 0.5 pF 22 pF 150 Ohm 10kOhm 0.8 pF BFP420 AN015_PCB_Layout.vsd Figure 2 PCB Layout and Component Placement Application Note 5 Rev. 2.0, 2006-11-14 Application Note No. 015 Low-Noise-Amplifier optimised for minimum Noise Figure at 1.9 GHz using Table 1 Component Component Value Unit Size Comment R1 10 kΩ 0603 Bias R2 150 Ω 0603 To improve stability and output return loss R3 150 Ω 0603 Bias resistor for BCR400W / collector current C1 0.5 pF 0603 Input match C2 0.8 pF 0603 Output match C3 22 pF 0603 RF-short C4 1 nF 0603 RF-short C5 4.7 µF 0603 RF-short C6 10 nF 0603 RF-short C7 22 pF 0603 RF-short C8 1 nF 0603 RF-short SOT343 SIEGET® BFP420 Tr1 TrL1 Input match TrL2 Emitter-microstrip-line TrL3 Emitter-microstrip-line TrL4 Output match IC1 Substrate Application Note SOT343 BCR400W, active bias controller h = 0.5 mm, εr = 4.5 FR4 6 Rev. 2.0, 2006-11-14 Application Note No. 015 Low-Noise-Amplifier optimised for minimum Noise Figure at 1.9 GHz using Measurements 10.000 dB/DIV S21 LOG MAG. S12 LOG MAG. 10.000 dB/DIV 1 1 S11 0.100000 3.000000 GHz 0.100000 LOG MAG. 10.000 dB/DIV S22 3.000000 GHz LOG MAG. 10.000 dB/DIV 1 1 GHz 0.100000 1 3.000000 0.100000 GHz 3.000000 1.9 GHz AN015_M easurem ents.vsd Figure 3 Measurements Application Note 7 Rev. 2.0, 2006-11-14