A pp l ic a t io n N o t e, R e v . 2. 0 , J a n. 2 00 7 A p p li c a t i o n N o t e N o . 0 3 1 A L o w N o i s e A m p l i f i e r a t 1 . 9 G H z o ff e r s + 1 4 d B m Input Intercept Point R F & P r o t e c ti o n D e v i c e s Edition 2007-01-08 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. 031 Application Note No. 031 Revision History: 2007-01-08, Rev. 2.0 Previous Version: Page Subjects (major changes since last revision) Trademarks SIEGET® is a registered trademark of Infineon Technologies AG. Application Note 3 Rev. 2.0, 2007-01-08 Application Note No. 031 A Low Noise Amplifier at 1.9 GHz offers +14 dBm Input Intercept Point 1 A Low Noise Amplifier at 1.9 GHz offers +14 dBm Input Intercept Point 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 Infineon SIEGET BFP450. The emphasis has been on high IP3in -values Data at 1.9 GHz (3 V and 24 mA / R1 = 33, R2 = 5.6 k) Gain: 11 dB IP3out: NF: RLin-out 14 dBm 1.9 dB >10 dB Data at 1.9 GHz (3 V and 15 mA / R1 = 56, R2 = 8.2 k) Gain: 10.5 dB IP3out: NF: RLin-out 10 dBm 1.8 dB >10 dB +3V C5=100pF C6=10nF R1=33 Ohm C4=10pF R2=5.6k TrL4 C3=10pF C2=100pF RFout R3=33 Ohm C1=0.8pF TrL1 TrL3 RFin Tr1=BFP450 TrL2 TrL5 TrL6 AN031_Application.vsd Figure 1 Application This amplifier at 1.9 GHz has been realized by using microstrip lines for matching purposes. It offers a good compromise between low noise and high IIP3 values.For optimizing and improving the circuit please observe the following abstract: • • The layout size can be reduced by using chip-inductors instead of the microstrip lines TrL1 and TrL4 You are able to get a better stabilization behaviour versus temperature and a reduction of current gain distribution problems it you add a Infineon active bias controller BCR400W. This is easily done by replacing collector resistor R1 and by adding two capacitors. For further information please refer to application note No 014. However the resistor R1 and R2 are sufficient in most applications for stabilization purposes. Application Note 4 Rev. 2.0, 2007-01-08 Application Note No. 031 A Low Noise Amplifier at 1.9 GHz offers +14 dBm Input Intercept Point • • The measured figures include losses of SMA-connectors and the relatively high loss of the microstrip lines on the epoxy-board. Resistor R3 is used get higher circuit-stability at low frequencies. scale 1:1 dim.: 25mm x 28.5mm 10nF 100pF 10pF 33 Ohm 33 Ohm plated thru holes 10pF 5.6kOhm 0.8pF 100pF BFP450 AN031_PCB_layout.vsd Figure 2 PCB Layout and Component Placement Application Note 5 Rev. 2.0, 2007-01-08 Application Note No. 031 A Low Noise Amplifier at 1.9 GHz offers +14 dBm Input Intercept Point Table 1 Component Component Value Unit Size R1 33 Ω 0603/0805 Bias / collector-resistance / VR1 ≅ 0.7 V R2 5.6 kΩ 0603/0805 Bias R3 33 Ω 0603/0805 To improve AF-stability C1 0.8 pF 0603/0805 Input match C2 100 pF 0603/0805 DC-block C3 10 pF 0603/0805 RF-short C4 10 pF 0603/0805 RF-short C5 100 pF 0603/0805 RF-short C6 10 nF 0603/0805 RF-short Tr1 Comment SIEGET® BFP450 SOT343 TrL1 Input match, w = 0.3 mm TrL2 Input match, w = 0.8 mm TrL3 Output match, w = 1.9 mm TrL4 Output match, w = 0.3 mm TrL5 Emitter inductance, w = 1.9 mm TrL6 Emitter inductance, w = 1.9 mm Substrate Application Note h = 1 mm, er = 4.5 FR4 6 Rev. 2.0, 2007-01-08 Application Note No. 031 A Low Noise Amplifier at 1.9 GHz offers +14 dBm Input Intercept Point Measured data +V = 3 Vdc / I = 24 mA (R1 = 33 Ω, R2 = 5.6 kΩ) S21 LOG MAG. S12 10.000 dB/DIV LOG MAG. 10.000 dB/DIV 1 1 0.040000 S11 GHz 3.000000 0.040000 10.000 dB/DIV LOG MAG. S22 GHz 3.000000 10.000 dB/DIV LOG MAG. 1 1 0.040000 1 GHz 3.000000 0.040000 GHz 3.000000 1.9 GHz AN031_M easured_data_24m A.vsd Figure 3 Measured data Application Note 7 Rev. 2.0, 2007-01-08 Application Note No. 031 A Low Noise Amplifier at 1.9 GHz offers +14 dBm Input Intercept Point Measured data +V = 3 Vdc / I = 15 mA (R1 = 56 Ω, R2 = 8.2 kΩ) S21 LOG MAG. 10.000 dB/DIV S12 10.000 dB/DIV LOG MAG. 1 1 0.040000 S11 GHz LOG MAG. 0.040000 3.000000 10.000 dB/DIV S22 GHz LOG MAG. 3.000000 10.000 dB/DIV 1 1 0.040000 1 GHz 3.000000 0.040000 GHz 3.000000 1.9 GHz AN031_M easured_data_15m A.vsd Figure 4 Measured data Application Note 8 Rev. 2.0, 2007-01-08