#72 Noise figure of amplifier

closed-fixed
Stefan Jahn
None
5
2011-03-01
2010-05-21
Frans
No

Hi, In the Amplifier component (found in lumped components), the noise figure seems to be calculated on the output of the amplifier. I think it should be on the input since the noise figure changes now as you vary the gain.
With a gain of 10 and NF of 7dB, it gives a noise figure of 0.519dB instead. When the gain is 1, the noise figure is 7dB as expected.
qucs version: trunk

Kind regards,

Frans Schreuder

Discussion

  • Frans
    Frans
    2010-05-21

    demonstration of the bug

     
    Attachments
  • Stefan Jahn
    Stefan Jahn
    2011-03-01

    Hello Frans,

    I think I fixed that 1 year ago in CVS...

    Best regards, Stefan.

     
  • Stefan Jahn
    Stefan Jahn
    2011-03-01

    • assigned_to: nobody --> ela
    • status: open --> closed-fixed