BGA430 Datasheet, PDF (1/24 Pages) Infineon Technologies AG – A 35 dB Gain-Sloped LNB I.F. Amplifier for Direct Broadcast Satellite Television Applications using the BGA430 & BGB540 Silicon MMICs

Applications Note No. 074
Silicon Discretes
A 35 dB Gain-Sloped LNB I.F. Amplifier for Direct Broadcast Satellite
Television Applications using the BGA430 & BGB540 Silicon MMICs
• Gain = 32 – 37 dB from 950 – 2150 MHz (positive gain slope)
• Low Power Consumption: 40mA at +5.0 Volts
• Exceptionally low Noise Figure: less than 3 dB
• Low Cost, Low Parts Count
• High Reverse Isolation
• Output Compression point: +1 dBm minimum
(May be increased with higher DC bias level)
• Suitable for European, Asian & North American DBS
LNB I.F. Amplifier Chains for 950 – 1450 and 950 – 2150 MHz
1. Overview
Infineon’s BGA430 Broad Band High Gain
Low Noise Amplifier and BGB540 Active
Biased Transistor are shown in an
Intermediate-Frequency (“I.F.”) amplifier
application targeted for the I.F. chains of
European, Asian and North American Direct-
Broadcast Satellite (DBS) Low Noise Block
Amplifier / Downconverters (LNBs).
A summary of key performance parameters for
the complete LNB I.F. Amplifier is given in Table
1 to the right. The reader is referred to
Appendix A on page 21 for complete electrical
data including minimum, maximum, mean value,
and standard deviation for the lot of Printed
Circuit Boards (PCBs) tested. Appendix B on
page 22 gives information on performance over
the –40 to +85 °C temperature range.
Section 2 of this applications note provides a
brief description of the BGA430 and BGB540
MMICs. Section 3 gives some general Direct
Broadcast Satellite system information, and is
included to provide a general background.
Section 4 provides details on the PC Board
used, including photos, a Bill of Material (BOM)
and a PCB cross-sectional diagram. Section 5
describes using the BGA430 MMIC as a stand-
alone DBS I.F. Amplifier block, and covers
design issues unique to BGA430. Section 6
addresses the question “why might one want a
positive gain slope I.F. Amplifier” and Section 7
gives measurement results on the complete
gain-sloped amplifier using both BGA430 &
BGB540.
Table 1.
complete
Amplifier.
Typical performance for the
BGA430+BGB540 LNB I.F.
Conditions: Temperature=25°C, V=5.0 Volts, n=25 units,
Z_S=Z_L=50Ω, network analyzer source power = -40 dBm
Parameter
Input Return Loss, dB
Gain, dB
Reverse Isolation, dB
Output Return Loss, dB
Noise Figure, dB
Output P_1dB, dBm
Input IP₃, dBm
Frequency, MHz
950 1450 2150
26.0 27.3 12.0
33.0 37.2 37.2
>50
>50
>50
13.7 13.4 13.1
2.4
2.4
2.6
+1.7 +4.9 +7.9
-20.8 -22.5 -18.9
Please note that the reference planes for all
measurement data shown in Table 1 are at the
PC board’s SMA RF connectors; e.g. no PCB
loss is extracted from the numbers given.
AN 074 Rev E
1 / 24
19-November-2002