[VHFcontesting] PA Question

John Santillo u1004467 at warwick.net
Tue Oct 23 21:39:40 EDT 2012


Hello,

 

I have a PA Noise Figure Question.  

 

If a power amplifier has a Noise Figure of say 7dB and a series pad of 10dB
is added does the Friss Equation hold true for calculating the increased
Noise Figure?  For example, using the equation below I calculated a Noise
Figure of just over 19dB with the pad inline.  If this is the case, can the
carrier coming out of the PA be overwhelmed by the noise?  

 

Is the 7dB Noise Figure really the noise out of an amplifier with the input
terminated above kTB?

 

 

Ft = F1 + ( F2-1) / G1 

 

 

Thanks in advance,

 

73,

 

John

N2HMM

 



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