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 7 0 H i g h R e v e r s e I s o l at i o n A m p l i f i e r s at 90 0 M H z a n d 1800 MHz using BGA416 R F & P r o t e c ti o n D e v i c e s Edition 2007-01-04 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. 070 Application Note No. 070 Revision History: 2007-01-04, Rev. 2.0 Previous Version: 2000-02-03 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, 2007-01-04 Application Note No. 070 High Reverse Isolation Amplifiers at 900 MHz and 1800 MHz using BGA416 1 High Reverse Isolation Amplifiers at 900 MHz and 1800 MHz using BGA416 Features • High Maximum Available Gain of 23 dB at 900 MHz • Ultra high reverse isolation of 62 dB at 900 MHz • Integrated on-chip biasing circuit • Low Noise Figure of 1.3 dB at 900 MHz Applications • High Reverse Isolation buffer amplifier for oscillator applications • Low Noise Amplifier for 800 / 900 MHz, GMS900, 900 MHz ISM, DCS1800, GPS, 1900 MHz PCS, WLAN, UMTS • Active element in oscillator circuits GND, 1 4, RFout RFin, 2 3, GND 3 2 4 1 Top View AN070_pin_connection.vsd Figure 1 PIN configuration 1.1 Introduction The BGA416 is a monolithic cascode amplifier realized in Infineon Technologies’ SIEGET®25 bipolar process. The cascode amplifier is a popular transistor configuration used in many RF functional blocks such as low noise amplifiers, voltage controlled oscillators, buffer amplifiers and others for a wide variety of RF and Wireless end products. GND, 1 Bias RFout, 4 RFin, 2 GND, 3 AN070_schematic.vsd Figure 2 Schematic Diagram BGA416 Application Note 4 Rev. 2.0, 2007-01-04 Application Note No. 070 The BGA416 in a 900 MHz Amplifier Application The BGA416 features an integrated, on-chip bias circuit that sets the device’s bias point resulting in a low total parts-count and reduction in required printed circuit board area. RF impedance matching is done off-chip to allow maximum flexibility, enabling the BGA416 to be used in a wide variety of applications. 2 The BGA416 in a 900 MHz Amplifier Application 900 MHz circuit Vcc C3 100pF L3 10nH C4 1.2pF Out 4 1 IC1 BGA416 In L1 10nH C1 100pF 2 3 AN070_Application_circuit_900MHz.vsd Figure 3 900 MHz Application Circuit Diagram Table 1 Bill of Material of 900 MHz Circuit Name Value Unit Package Manufacturer Function C1 100 pF 0402 Various DC block C2 1.2 pF 0402 Various Output matching, DC block C3 100 pF 0402 Various RF bypass IC1 BGA416 SOT143 Infineon Technologies Si MMIC L1 10 nH 0402 Toko LL1005-FH Input matching L2 10 nH 0402 Toko LL1005-FH Output matching, RF choke 2.1 Performance Overview The following table shows the measured performance of the application circuit in Figure 3. All measurement values presented in this application note include losses of both PCB and connectors - in other words, the reference planes used for measurements are the PCB’s RF SMA connectors. Noise figure and gain results shown do not have any PCB loss extracted from them. Table 2 Measured Performance Data at 900 MHz and VCC = 3 V Parameter Symbol Value Unit Supply current ICC |S21|² NF |S11|² |S22|² |S12|² 5.4 mA 20.6 dB 1.7 dB 13.9 dB 11.6 dB 62 dB Insertion power gain Noise figure Input return loss Output return loss Reverse isolation Application Note 5 Rev. 2.0, 2007-01-04 Application Note No. 070 The BGA416 in a 900 MHz Amplifier Application Table 2 Measured Performance Data at 900 MHz and VCC = 3 V (cont’d) Parameter Input 1 dB-compression point Input third order intercept point 1) ∆f = 1 MHz; Pin = -35 dBm 1) Symbol Value Unit IP1dB IIP3 -17.5 dBm -8.8 dBm 22 Gain [dB] 21 20 19 18 17 0.86 0.88 0.9 0.92 0.94 Frequency [GHz] AN070_Gain(f)_900MHz.vsd Figure 4 Insertion Power Gain Return Loss [dB] 6 8 10 12 s11 s22 14 16 0.86 0.88 0.9 0.92 0.94 Frequency [GHz] AN070_Return_Loss(f)_900MHz.vsd Figure 5 Return Loss Application Note 6 Rev. 2.0, 2007-01-04 Application Note No. 070 The BGA416 in a 900 MHz Amplifier Application Reverse Isolation [dB] 40 45 50 55 60 65 70 75 80 0.86 0.88 0.9 0.92 0.94 Frequeny [GHz] AN070_Reverse_Isolation(f)_900MHz.vsd Figure 6 Reverse Isolation 14 12 K, B1 10 K 8 6 4 2 B1 0 0 1 2 3 4 Frequency [GHz] AN070_K_B1(f)_900MHz.vsd Figure 7 Stability Application Note 7 Rev. 2.0, 2007-01-04 Application Note No. 070 The BGA416 in a 900 MHz Amplifier Application 25 20 Gain [dB] 15 10 5 0 -5 -10 -15 -20 0 1 2 3 4 Frequency [GHz] AN070_Gain(f)_WS_900MHz.vsd Figure 8 Wide Span Gain -5 s11 Return Loss [dB] 0 s22 5 10 15 20 25 0 1 2 3 4 Frequency [GHz] AN070_Return_Loss(f)_WS_900MHz.vsd Figure 9 Wide Span Return Loss Application Note 8 Rev. 2.0, 2007-01-04 Application Note No. 070 4 24 2 23 0 22 -2 21 Gain -4 20 -6 19 -8 18 -10 17 Pout -12 Gain [dB] Pout [dBm] The BGA416 in a 1800 MHz Amplifier Application 16 -14 15 -35 -30 -25 -20 -15 Pin [dBm] AN070_Pout(Pin)_WS_900MHz.vsd Figure 10 Gain Compression 3 The BGA416 in a 1800 MHz Amplifier Application 1800 MHz Circuit Vcc C3 10pF L3 2.2nH C4 1.2pF Out 4 1 IC1 BGA416 In C1 270pF L1 4.7nH 2 3 AN070_Application_circuit_1800MHz.vs Figure 11 1800 MHz Application Circuit Diagram Table 3 Bill of Material of 1800 MHz Circuit Name Value Unit Package Manufacturer Function C1 270 pF 0402 Various DC block C2 1.2 pF 0402 Various Output matching, DC block C3 10 pF IC1 BGA416 L1 4.7 L2 2.2 Application Note 0402 Various RF bypass SOT143 Infineon Technologies Si MMIC nH 0402 Toko LL1005-FH Input matching nH 0402 Toko LL1005-FH Output matching RF choke 9 Rev. 2.0, 2007-01-04 Application Note No. 070 The BGA416 in a 1800 MHz Amplifier Application 3.1 Performance Overview The following table shows the measured performance of the application circuit in Figure 11. As mentioned before all these values were measured at the SMA connectors of the application PCB. Table 4 Measured Performance Data at 1800 MHz and VCC = 3 V Parameter Symbol Value Unit Supply current ICC |S21|² NF |S11|² |S22|² |S12|² IP1dB IIP3 5.4 mA 12.9 dB 2.1 dB 19.4 dB 23.9 dB 38 dB -13.5 dBm -3 dBm Insertion power gain Noise figure Input return loss Output return loss Reverse isolation Input 1 dB-compression point Input third order intercept point 1) 1) ∆f = 1 MHz; Pin = -35 dBm 15 Gain [dB] 14 13 12 11 10 1.7 1.75 1.8 1.85 1.9 Frequency [GHz] AN070_Gain(f)_1800MHz.vsd Figure 12 Insertion Power Gain Application Note 10 Rev. 2.0, 2007-01-04 Application Note No. 070 The BGA416 in a 1800 MHz Amplifier Application 8 Return Loss [dB] 10 s22 12 14 16 s11 18 20 22 24 26 1.7 1.75 1.8 1.85 1.9 Frequency [GHz] AN070_Return_Loss(f)_1800MHz.vsd Figure 13 Return Loss Reverse Isolation [dB] 32 34 36 38 40 42 1.7 1.75 1.8 1.85 1.9 Frequeny [GHz] AN070_Reverse_Isolation(f)_1800MHz.vsd Figure 14 Reverse Isolation Application Note 11 Rev. 2.0, 2007-01-04 Application Note No. 070 The BGA416 in a 1800 MHz Amplifier Application 14 12 K, B1 10 K 8 6 4 2 B1 0 0 1 2 3 4 Frequency [GHz] AN070_K_B1(f)_1800MHz.vsd Figure 15 Stability 15 10 Gain [dB] 5 0 -5 -10 -15 -20 0 1 2 3 4 Frequency [GHz] AN070_Gain(f)_WS_1800MHz.vsd Figure 16 Wide Span Gain Application Note 12 Rev. 2.0, 2007-01-04 Application Note No. 070 Application Board and Component Placement -5 s11 Return Loss [dB] 0 5 s22 10 15 20 25 30 0 1 2 3 4 Frequency [GHz] AN070_Return_Loss(f)_WS_1800MHz.vsd Wide Span Return Loss 0 15 Pout [dBm] -5 14 Gain -10 13 -15 12 -20 Gain [dB] Figure 17 11 Pout -25 10 -35 -30 -25 -20 -15 -10 Pin [dBm] AN070_Pout(Pin))_WS_1800MHz.vsd Figure 18 Gain Compression 4 Application Board and Component Placement Figure 19 shows the placement of the particular components on the application board. The element labeled “NA” is not used in the designs described in this application note. Figure 20 displays the cross section of the application PCB. The layer which is actually used for electrical / RF purposes is the layer with the 0.2 mm FR dielectric thickness. The 0.8 mm RF layer is used solely to provide mechanical rigidity and to allow for the use of edge-mount SMA RF connectors. Application Note 13 Rev. 2.0, 2007-01-04 Application Note No. 070 Application Board and Component Placement Vcc C3 8mm L2 NA C2 C1 RFout IC1 RFin L1 10mm AN070_Component_Placement.vs Figure 19 Component Placement on the Application PCB 0.2 mm FR4 35 µm Cu 35 µm Cu for mechanical rigidity of PCB 0.8 mm FR4 35 µm Cu AN070_PCB_Cross_Section.vsd Figure 20 PCB Cross Section Evaluation boards for the amplifier applications described in this application note are available form Infineon Technologies. Application Note 14 Rev. 2.0, 2007-01-04