Application Note No. 157

Transcription

1 Application Note, Rev. 1.2, April 2008 Application Note No. 157 BFP450 SIEGET Transistor as an 869 MHz Power Amp in an Alarm Transmitter Monitor Application RF & Protection Devices

2 Edition Published by Infineon Technologies AG München, Germany Infineon Technologies AG 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 ( 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.

3 Application Note No. 157 Revision History: , Rev. 1.2 Previous Version: , Rev. 1.1 Page Subjects (major changes since last revision) All Small changes in figure descriptions Application Note 3 Rev. 1.2,

4 1 Transmitter Monitor Application Overview The BFP450 SIEGET transistor in the B6HF process is shown as a low-cost discrete single-stage Class A RF "Power Amplifier" at 869 MHz for a European Alarm Transmitter Monitor. Application is mobile and runs from a battery. The BFP450 in the SOT343 package is shown as an alternative to a 2-stage Gallium Arsenide amplifier. Note the system power supply voltage is nominally 3.0 V, but can go down to 2.2 V when battery is discharged. Data is taken at both 3.0 and 2.2 V. Output 1 db gain compression point is dbm at 3.0 V, and drops to dbm at 2.2 V. A very simple bias circuit is used here, and therefore BFP450 collector current is directly proportional to supply voltage => decreased collector current at the reduced supply voltage gives rise to a drop in output P 1dB. It may be possible to mitigate P 1dB degradation via use of an active bias circuit. BFP450 amplifier is used in a standard BFP620 Version 1.0 PC board, with a sawed-off output. The PCB is made in standard low-cost FR-4 material. Standard low-cost chip components are used, in 0402 and 0603 case sizes. Total component count = 14, including BFP450 transistor, but excluding RF and DC Connectors. PCB Cross-Section Diagram Note PCB is low-cost, standard FR4 material. Figure 1 PCB - Cross Sectional Diagram Application Note 4 Rev. 1.2,

5 Summary of Data Table 1 Summary of Data, T =25 C Parameter Frequency Range DC Current DC Voltage, V CC Output P 1dB Output 3 rd Order Intercept Noise Figure Gain Input return loss Output return loss Reverse isolation Result / Value 869 MHz 869 MHz +/- 200 khz 68.5 ma, V Supply = 3.0 V 42.8 ma, V Supply = 2.2 V 3.0 V and 2.2 V V, 68.5 ma V, 42.8 ma V, 68.5 ma V, 42.8 ma V, 68.5 ma V, 42.8 ma V, 68.5 ma V, 42.8 ma V, 68.5 ma V, 42.8 ma V, 68.5 ma V, 42.8 ma V, 68.5 ma V, 42.8 ma Application Note 5 Rev. 1.2,

6 Bill of Material Table 2 Bill of Material Reference Value Manufacturer Case Size Function Designator C1 47 pf Various 0402 Input DC block C2 6.2 pf Various 0402 Input impedance match C3 0.1 µf Various 0402 Low frequency ground C4 47 pf Various 0402 RF bypass / RF block C5 0.1 µf Various 0603 Low frequency ground C6 47 pf Various 0402 RF bypass / RF block C7 47 pf Various 0402 Output DC block L1 3.9 nh Murata LQG10A low cost inductor 0402 Input impedance match L2 33 nh Murata LQG10A low cost inductor L3 8.2 nh Murata LQG10A low cost inductor 0402 RF choke on base (provides path for DC bias to base) RF choke on collector (provides path for DC bias to base, also influences output impedance match). R1 2.4 kω Various 0402 Bias to base of transistor. R2 2.2 Ω Various 0402 Bias resistor - provides small amount of DC negative feedback to transistor - to compensate for beta and temperature variations. R3 2.2 Ω Various 0402 Helps to stabilize transistor and ensure K>1 at low frequencies, also influences output match. Q1 - Infineon Technologies SOT343 BFP450 medium power transistor in B6HF bipolar process. J1, J2 - Johnson RF input / output connectors J3 - AMP 5 pin header MTA- 100 series (standard pin plating) or (gold plated pins) - DC connector Pins 1, 5 = ground Pin 3 = V CC Pins 2, 4 = no connection Application Note 6 Rev. 1.2,

7 Schematic Diagram Total parts count = 14, including BFP450, not including DC & RF connectors (7 capacitors, 3 resistors, 3 chip inductors, BFP450 transistor). Figure 2 Schematic Diagram Application Note 7 Rev. 1.2,

8 Noise Figure, Plot, 3.0 V, 68.5 ma. Center of Plot (x-axis) is 869 MHz. From Rohde & Schwarz FSEK3 + FESB30 System Preamplifier = MITEQ SMC-02 T = 25 C, 3.0 V, 68.5 ma Figure 3 Noise Figure Application Note 8 Rev. 1.2,

9 Noise Figure, Tabular Data, 3.0 V, 68.5 ma Table 3 Noise Figure, 3.0 V, 68.5 ma Frequency Noise Figure 819 MHz 2.15 db 829 MHz 2.20 db 839 MHz 2.24 db 849 MHz 2.27 db 859 MHz 2.33 db 869 MHz 2.36 db 879 MHz 2.42 db 889 MHz 2.46 db 899 MHz 2.53 db 909 MHz 2.59 db 919 MHz 2.65 db Application Note 9 Rev. 1.2,

10 Noise Figure, Plot, 2.2 V, 42.8 ma. Center of Plot (x-axis) is 869 MHz. From Rohde & Schwarz FSEK3 + FESB30 System Preamplifier = MITEQ SMC-02 T = 25 C, 2.2 V, 42.8 ma Figure 4 Noise Figure Application Note 10 Rev. 1.2,

11 Noise Figure, Tabular Data, 2.2 V, 42.8 ma Table 4 Noise Figure, 2.2 V, 42.8 ma Frequency Noise Figure 819 MHz 1.85 db 829 MHz 1.88 db 839 MHz 1.92 db 849 MHz 1.94 db 859 MHz 2.00 db 869 MHz 2.00 db 879 MHz 2.05 db 889 MHz 2.09 db 899 MHz 2.13 db 909 MHz 2.20 db 919 MHz 2.25 db Application Note 11 Rev. 1.2,

12 Stability Factors K and B 1, 3.0 V, 68.5 ma For unconditional stability, K > 1 and B1 > 0. Note actual S-parameters from LNA Circuit Board are imported into Ansoft Serenade, which then calculates and plots K and B 1. Note LNA is unconditionally stable from low frequencies up to 6 GHz. (Network analyzer upper frequency limit is 6 GHz.). Note red trace is K, blue trace is B 1. Figure 5 Plot of K(f) and B 1 (f) for 3.0 V, 68.5 ma Application Note 12 Rev. 1.2,

13 Stability Factors K and B 1, 2.2 V, 42.8 ma For unconditional stability, K > 1 and B1 > 0. Note actual S-parameters from LNA Circuit Board are imported into Ansoft Serenade, which then calculates and plots K and B 1. Note LNA is unconditionally stable from low frequencies up to 6 GHz. (Network analyzer upper frequency limit is 6 GHz.). Note red trace is K, blue trace is B 1. Figure 6 Plot of K(f) and B 1 (f) for 2.2 V, 42.8 ma Application Note 13 Rev. 1.2,

14 Scanned Image of PC Board (overall view) Figure 7 Image of PC Board Application Note 14 Rev. 1.2,

15 Scanned Image of PC Board (close-in view). Figure 8 Image of PC Board, close-in view Application Note 15 Rev. 1.2,

16 Amplifier Gain Compression at 869 MHz Table 5 Gain Compression at 869 MHz, T =25 C Power Supply Voltage Current Small Signal Gain Input P 1dB Output P 1dB 3.0 V 68.5 ma 21.5 db -1.5 dbm dbm 2.2 V 42.8 ma 21.2 db -4.5 dbm dbm Figure 9 Plot of Gain Compression Application Note 16 Rev. 1.2,

17 Input Return Loss, Log Mag Narrow Span, 3.0 V, 68.5 ma Figure 10 Plot of Input Return Loss, Narrow Span, 3.0 V, 68.5 ma Application Note 17 Rev. 1.2,

18 Input Return Loss, Smith Chart Reference Plane = PCB Input SMA Connector Narrow Span, 3.0 V, 68.5 ma Figure 11 Smith Chart of Input Return Loss, Narrow Span, 3.0 V, 68.5 ma Application Note 18 Rev. 1.2,

19 Forward Gain Narrow Span, 3.0 V, 68.5 ma Figure 12 Plot of Forward Gain, Narrow Span, 3.0 V, 68.5 ma Application Note 19 Rev. 1.2,

20 Reverse Isolation Narrow Span, 3.0 V, 68.5 ma Figure 13 Plot of Reverse Isolation, Narrow Span, 3.0 V, 68.5 ma Application Note 20 Rev. 1.2,

21 Output Return Loss, Log Mag Narrow Span, 3.0 V, 68.5 ma Figure 14 Plot of Output Return Loss, Narrow Span, 3.0 V, 68.5 ma Application Note 21 Rev. 1.2,

22 Output Return Loss, Smith Chart Reference Plane = PCB Input SMA Connector Narrow Span, 3.0 V, 68.5 ma Figure 15 Smith Chart of Output Return Loss, Narrow Span, 3.0 V, 68.5 ma Application Note 22 Rev. 1.2,

23 Input Return Loss, Log Mag Narrow Span, 2.2 V, 42.8 ma Figure 16 Plot of Input Return Loss, Narrow Span, 2.2 V, 42.8 ma Application Note 23 Rev. 1.2,

24 Input Return Loss, Smith Chart Reference Plane = PCB Input SMA Connector Narrow Span, 2.2 V, 42.8 ma Figure 17 Smith Chart of Input Return Loss, Narrow Span, 2.2 V, 42.8 ma Application Note 24 Rev. 1.2,

25 Forward Gain Narrow Span, 2.2 V, 42.8 ma Figure 18 Plot of Forward Gain, Narrow Span, 2.2 V, 42.8 ma Application Note 25 Rev. 1.2,

26 Reverse Isolation Narrow Span, 2.2 V, 42.8 ma Figure 19 Plot of Reverse Isolation, Narrow Span, 2.2 V, 42.8 ma Application Note 26 Rev. 1.2,

27 Output Return Loss, Log Mag Narrow Span, 2.2 V, 42.8 ma Figure 20 Plot of Output Return Loss, Narrow Span, 2.2 V, 42.8 ma Application Note 27 Rev. 1.2,

28 Output Return Loss, Smith Chart Reference Plane = PCB Input SMA Connector Narrow Span, 2.2 V, 42.8 ma Figure 21 Smith Chart of Output Return Loss, Narrow Span, 2.2 V, 42.8 ma Application Note 28 Rev. 1.2,

29 Input Return Loss, Log Mag Wide Span, 3.0 V, 68.5 ma Figure 22 Plot of Input Return Loss, Wide Span, 3.0 V, 68.5 ma Application Note 29 Rev. 1.2,

30 Input Return Loss, Smith Chart Reference Plane = PCB Input SMA Connector Wide Span, 3.0 V, 68.5 ma Figure 23 Smith Chart of Input Return Loss, Wide Span, 3.0 V, 68.5 ma Application Note 30 Rev. 1.2,

31 Forward Gain Wide Span, 3.0 V, 68.5 ma Figure 24 Plot of Forward Gain, Wide Span, 3.0 V, 68.5 ma Application Note 31 Rev. 1.2,

32 Reverse Isolation Wide Span, 3.0 V, 68.5 ma Figure 25 Plot of Reverse Isolation, Wide Span, 3.0 V, 68.5 ma Application Note 32 Rev. 1.2,

33 Output Return Loss, Log Mag Wide Span, 3.0 V, 68.5 ma Figure 26 Plot of Output Return Loss, Wide Span, 3.0 V, 68.5 ma Application Note 33 Rev. 1.2,

34 Output Return Loss, Smith Chart Reference Plane = PCB Input SMA Connector Wide Span, 3.0 V, 68.5 ma Figure 27 Smith Chart of Output Return Loss, Wide Span, 3.0 V, 68.5 ma Application Note 34 Rev. 1.2,

35 Input Return Loss, Log Mag Wide Span, 2.2 V, 42.8 ma Figure 28 Plot of Input Return Loss, Wide Span, 2.2 V, 42.8 ma Application Note 35 Rev. 1.2,

36 Input Return Loss, Smith Chart Reference Plane = PCB Input SMA Connector Wide Span, 2.2 V, 42.8 ma Figure 29 Smith Chart of Input Return Loss, Wide Span, 2.2 V, 42.8 ma Application Note 36 Rev. 1.2,

37 Forward Gain Wide Span, 2.2 V, 42.8 ma Figure 30 Plot of Forward Gain, Wide Span, 2.2 V, 42.8 ma Application Note 37 Rev. 1.2,

38 Reverse Isolation Wide Span, 2.2 V, 42.8 ma Figure 31 Plot of Reverse Isolation, Wide Span, 2.2 V, 42.8 ma Application Note 38 Rev. 1.2,

39 Output Return Loss, Log Mag Wide Span, 2.2 V, 42.8 ma Figure 32 Plot of Output Return Loss, Wide Span, 2.2 V, 42.8 ma Application Note 39 Rev. 1.2,

40 Output Return Loss, Smith Chart Reference Plane = PCB Input SMA Connector Wide Span, 2.2 V, 42.8 ma Figure 33 Smith Chart of Output Return Loss, Wide Span, 2.2 V, 42.8 ma Application Note 40 Rev. 1.2,

41 Low Voltage, V Supply =2.2V, V CE =2.0V, I =42.8mA Output Response of Amplifier to Two-Tone 3 rd Order Intercept Test Input Stimulus: f 1 = 869 MHz, f 2 = 870 MHz, -17 dbm each tone, tone spacing = 1 MHz. Input IP 3 = (45.8 / 2) = +5.9 dbm Output IP 3 = +5.9 dbm + Gain = +5.9 dbm dbm = dbm Figure 34 Plot of Tow-Tone Test, LNA response, 2.2 V, 42.8 ma Application Note 41 Rev. 1.2,

42 High Voltage, V Supply =3.0V, V CE =2.7V, I = 68.5 ma Output Response of Amplifier to Two-Tone 3 rd Order Intercept Test Input Stimulus: f 1 = 869 MHz, f 2 = 870 MHz, -17 dbm each tone, tone spacing = 1 MHz. Input IP 3 = (50.8 / 2) = +8.4 dbm Output IP 3 = +8.4 dbm + Gain = +8.4 dbm dbm = dbm Figure 35 Plot of Tow-Tone Test, LNA response, 3.0 V, 68.5 ma Application Note 42 Rev. 1.2,