BGB540

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 of BGB540 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, nd 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.