Application Note, Rev. 1.1, April 2012 Application Note No. 098 Broadband Amplifier MMICs for TV Tuner Applications RF & Protection Devices Edition 2012-04-25 Published by Infineon Technologies AG 81726 München, Germany © Infineon Technologies AG 2012. 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. 098 Application Note No. 098 Revision History: 2012-04-25, Rev. 1.1 Previous Version: 2006-11-28, Rev. 1.0 Page Subjects (major changes since last revision) 7 Bill of Matrials updated Application Note 3 Rev. 1.1, 2012-04-25 Application Note No. 098 Broadband Amplifier MMICs in TV Tuner Applications 1 Broadband Amplifier MMICs in TV Tuner Applications Over the last few years there has been a clear trend in television to move from the classical TV-set out to more mobile platforms like notebooks, cell phones and PDAs. Especially the introduction of digital terrestrial television in many countries and the more and more evolving hand-held television standards like DVB-H and T-DMB support this evolution. With television going mobile the antennas are getting smaller, resulting in a loss in antenna gain. It requires an additional LNA with low noise figure to keep up a good reception of the TV signal, no matter if the TV tuner’s RF frontend uses the classical three-band tuner (Figure 1) or the more space saving silicon tuner (also called double conversion tuner or up-down converter, Figure 2). Particularly the silicon tuner has the need for and external LNA as tuner ICs in general tend to have high noise figures and the silicon tuner approach doesn’t implement any prestages including an RF MOSFET. LNAs for TV tuner applications have to fulfill challenging requirements. They have to cover a very wide frequency range and need to handle both extremely high and low signal levels at the amplifiers input. These different signal levels require an LNA that offers both a good noise figure as well as a high linearity. Broadband design, low noise figure and high linearity make Infineon’s Darlington broadband amplifier family the LNAs of choice for TV tuner applications. VHF low 47 ... 160MHz RF Input VHF high 160 ... 470MHz LNA Tuner IC ESD Protection UHF 470 ... 860MHz 3Band.vsd RF MOSFETs Figure 1 Classical Three-Band Tuner SAW GSM Rejection LNA Demod ESD Protection VGA Mixer VCO 1 Si-Tuner Figure 2 Mixer VCO 2 Si_Tuner.vsd Silicon Tuner Application Note 4 Rev. 1.1, 2012-04-25 Application Note No. 098 Infineon’s Darlington Broadband Amplifier Family 2 Infineon’s Darlington Broadband Amplifier Family 2.1 Description of the Devices Infineon’s Darlington amplifier family consists of three different LNAs: • • • BGA612 BGA614 BGA616 Out, 3 In, 1 GND, 2,4 Figure 3 schematic1.vsd Equivalent Circuit of the Broadband LNAs These types are matched, general purpose broadband MMIC amplifiers in Darlington configuration. They are implemented in Infineon’s high ft, low noise B7HF Silicon Germanium technology. The devices’ 3 dB bandwidth covers DC up to 2.7 GHz, Table 1 shows a collection of the most important electrical parameters of the three amplifiers. This data is an excerpt of the devices’ data sheets and does not contain any external losses. Table 1 Comparison of Key Parameters1) Parameter BGA612 BGA614 BGA616 Unit 20 40 60 mA Gain 17.0 18.5 18.5 dB Noise Figure 2.25 2.2 2.8 dB Input 1dB Compression Point -9 -6 0 dBm Input 3rd Order Intercept Point 0 6 11 dBm >15 >15 >15 dB Typ. operating current Return Loss 1) Measured at 1 GHz This exceptional performance, enabled by Infineon’s 70 GHz B7HF Silicon Germanium process, combined with reduced external component count and ease of use, make these broadband amplifiers an ideal choice for a wide variety of RF applications up to 2.5 GHz. The high linearity make them especially useful for TV applications. The Darlingtons’ simplicity, flexibility and ease of use streamlines the RF design process and allows for shorter design cycles and fast time-to-market in today’s fast-paced competitive business environment Application Note 5 Rev. 1.1, 2012-04-25 Application Note No. 098 Infineon’s Darlington Broadband Amplifier Family 2.2 TV Amplifier Design using BGA614 This chapter describes the design of a general purpose broadband amplifier for the frequency band between 50 MHz and 1 GHz using BGA614 as an example. Designing an amplifier with BGA612 or BGA616 is almost exactly the same procedure, they require only different bias resistors. Implementing an amplifier circuit using BGA614 is a simple straightforward task. As both input and output are matched and BGA614 is an unconditionally stable device, there is no need to work on the RF portion of the amplifier design, leaving only DC biasing issues to contend with. The broadband 50 Ω match also eases and speeds integration of the MMIC with any external filters used. Figure 5 and Table 2 show the typical schematic and bill of material when using one of the three MMICs as an LNA in TV tuner applications. Device Current I D = f(VCC) RBias = parameter in Ω 80 0 70 16 27 47 60 68 I D [mA] 50 40 100 30 150 20 10 0 0 1 2 3 4 5 6 VCC [V] Figure 4 Device Current vs. Supply Voltage, Parameter is R1 The Darlingtons are biased via their RF output pin (pin 3). Figure 4 shows the dependence of BGA614’s current consumption on the supply voltage for different values of the bias Resistor R1. R1 stabilizes the supply current by using voltage feedback. For BGA612 and BGA616 exist similar plots which can be found in the devices’ data sheets. In principle it is possible to bias BGA614 without an additional resistor. However, omitting R1 will lead to increased unit-to-unit variation in operating current due to the usual variation in the DC Beta (hFE) of the internal transistor cells. It is therefore recommended that R1 be used in all cases. The inductor L1 in series with resistor R1 is necessary for RF blocking. C3 and C4 serve as RF bypass at the voltage supply. The capacitors C1 and C2 are DC blocks as there is DC voltage present on pin 1 and pin 3. These capacitors are needed only if there is no DC open circuit on the input and output of the amplifier. For example, if a filter that presents a DC open circuit is used ahead of or after the BGA614, the corresponding DC blocking capacitor may be omitted. Application Note 6 Rev. 1.1, 2012-04-25 Application Note No. 098 Infineon’s Darlington Broadband Amplifier Family Vcc 5V C4 8.2nF R1 see BOM C1 8.2nF In 1 L1 270nH 4 Q1 BGA61x 2 C3 8.2nF C2 8.2nF 3 Out schematic.vsd Figure 5 Typical Schematic Table 2 Bill of Materials Name Unit Manufacturer Function C1 8.2 nF Various DC block C2 8.2 nF Various DC block C3 8.2 nF Various RF bypass C4 8.2 nF Various RF bypass L1 270 nH Various RF choke R1 120 @ BGA612 68 @ BGA614 15 @ BGA616 Ω Various Biasing Q1 BGA612 BGA614 BGA616 Infineon Technologies Broadband SiGe MMIC Application Note Value 7 Rev. 1.1, 2012-04-25 Application Note No. 098 Measurement Results 3 Measurement Results Please note that the data displayed in the following chapters includes connector losses as well as board losses. In other words, the reference planes of the measurements are the input and output connectors. 3.1 BGA612 Table 3 Measured Electrical Performance on Evaluation Board1) Parameter 50 MHz 500 MHz 1000 MHz Unit Supply Voltage 5 V Biasing Resistor 120 Ω DC current 20.8 mA Gain 17.0 17.4 16.7 dB Noise Figure 2.2 2.4 2.25 dB -11 -10 -10 dBm Input 1dB Compression Point rd Input 3 Order Intercept Point 2) 3) --- 2.5 1.5 dBm Input Return Loss 11.3 17.1 14.3 dB Output Return Loss 9.7 17.1 14.9 dB Reverse Isolation 20.6 20.4 20.5 dB 1) Including all PCB losses 2) Input power -25 dBm / tone; Δf = 1 MHz 3) No power combiner for this frequency available in lab 18 Gain (dB) 16 14 12 10 8 50 100 1000 Frequency (MHz) 5000 Gain_612.vsd Figure 6 Gain vs. Frequency Application Note 8 Rev. 1.1, 2012-04-25 Application Note No. 098 Measurement Results 0 Matching (dB) -5 -10 S22 -15 S11 -20 -25 50 100 1000 Frequency (MHz) 5000 s1122_612.vsd Figure 7 Input Return Loss and Output Return Loss vs. Frequency Reverse Isolation (dB) -5 -10 -15 -20 -25 50 100 1000 Frequency (MHz) 5000 S12_612.vsd Figure 8 Reverse Isolation vs. Frequency Application Note 9 Rev. 1.1, 2012-04-25 Application Note No. 098 Measurement Results Stability Factor / Measure 2 1.5 K>1 1 B1>0 0.5 0 50 100 1000 Frequency (MHz) 5000 K_612.vsd Figure 9 Stability Factor K and Stability Measure B1 vs. Frequency Application Note 10 Rev. 1.1, 2012-04-25 Application Note No. 098 Measurement Results 3.2 BGA614 Table 4 Measured Electrical Performance on Evaluation Board1) Parameter 50 MHz 500 MHz 1000 MHz Unit Supply Voltage 5 V Biasing Resistor 68 Ω DC current 39.2 mA Gain 18.7 19.0 18.1 dB Noise Figure 2.15 2.35 2.2 dB -6.5 -5.5 -5 dBm 3) --- 4.5 4.5 dBm 11.6 17.5 14.3 dB Input 1dB Compression Point rd Input 3 Order Intercept Point 2) Input Return Loss Output Return Loss 9.8 17.6 15.3 dB Reverse Isolation 22.4 21.7 21.6 dB 1) Including all PCB losses 2) Input power -20 dBm / tone; Δf = 1 MHz 3) No power combiner for this frequency available in lab 20 18 Gain (dB) 16 14 12 10 8 50 100 1000 Frequency (MHz) 5000 Gain_614.vsd Figure 10 Gain vs. Frequency Application Note 11 Rev. 1.1, 2012-04-25 Application Note No. 098 Measurement Results 0 Matching (dB) -5 -10 S22 -15 S11 -20 -25 50 100 1000 Frequency (MHz) 5000 S1122_614.vsd Figure 11 Input Return Loss and Output Return Loss vs. Frequency Reverse Isolation (dB) -5 -10 -15 -20 -25 50 100 1000 Frequency (MHz) 5000 s12_614.vsd Figure 12 Reverse Isolation vs. Frequency Application Note 12 Rev. 1.1, 2012-04-25 Application Note No. 098 Measurement Results Stability Factor / Measure 2 1.5 K>1 1 B1>0 0.5 0 50 100 1000 Frequency (MHz) 5000 K_614.vsd Figure 13 Stability Factor K and Stability Measure B1 vs. Frequency Application Note 13 Rev. 1.1, 2012-04-25 Application Note No. 098 Measurement Results 3.3 BGA616 Table 5 Measured Electrical Performance on Evaluation Board1) Parameter 50 MHz 500 MHz 1000 MHz Unit Supply Voltage 5 V Biasing Resistor 15 Ω DC current 59.6 mA Gain 18.5 19.0 18.1 dB Noise Figure 2.8 2.9 2.8 dB -1 0 1 Input 1dB Compression Point rd Input 3 Order Intercept Point 2) 3) Input Return Loss --- 9 11.6 17.5 dBm dBm 14.3 dB Output Return Loss 9.8 17.6 15.3 dB Reverse Isolation 22.4 21.7 21.6 dB 1) Including all PCB losses 2) Input power -20 dBm / tone; Δf = 1 MHz 3) No power combiner for this frequency available in lab 20 Gain (dB) 18 16 14 12 10 50 100 1000 Frequency (MHz) 5000 Gain_616.vsd Figure 14 Gain vs. Frequency Application Note 14 Rev. 1.1, 2012-04-25 Application Note No. 098 Measurement Results 0 Matching (dB) -5 -10 S22 -15 S11 -20 -25 50 100 1000 Frequency (MHz) 5000 s1122_616.vsd Figure 15 Input Return Loss and Output Return Loss vs. Frequency Reverse Isolation (dB) -5 -10 -15 -20 -25 50 100 1000 Frequency (MHz) 5000 S12_616.vsd Figure 16 Reverse Isolation vs. Frequency Application Note 15 Rev. 1.1, 2012-04-25 Application Note No. 098 Measurement Results Stability Factor / Measure 2 1.5 K>1 1 B1>0 0.5 0 50 100 1000 Frequency (MHz) 5000 K_616.vsd Figure 17 Stability Factor K and Stability Measure B1 vs. Frequency Application Note 16 Rev. 1.1, 2012-04-25