AnsweredAssumed Answered

Noise Figure Tuning Network

Question asked by Stephen Pflanze on Nov 16, 2017
Latest reply on Nov 28, 2017 by LPP

In spec sheets such as this one:

https://community.nxp.com/external-link.jspa?url=https%3A%2F%2Fwww.nxp.com%2Fdocs%2Fen%2Fdata-sheet%2FBFT25A.pdf 

there is are smith charts showing noise figure versus reflection coefficient data. In these smith charts does the reflection coefficient plotted in them show what it would without the transistor connected and the tuning network alone, or does it show what it is with the transistor connected?

 

In other words, to calculate what component values the tuning network had to have for any given reflection coefficient does the transistor base terminal's hybrid pi parameters have to be taken into account?

 

In that spec sheet's Tables 8 and 9 on page 7, and Table 10 on page 8 there is an Rn/50 column. What is Rn?

Outcomes