A noise figure is a scale of decibels.

hi

as we know noise temperature relate to noise figure as .................

T = T0(NF-1)

where T0 is referance figure and NF is noise figure

NF = (S/N)in

---------

(S/N)out

S/N is signal to noise ratio

say,

overall noise figure =f

noise figure of stage1=f1

noise figure of stage2=f2

f=f1+(f2-1)/g1

f1,f2 are in linear scale(not in dB)

g1=gain in stage1

Noise figure is one of those cases that is crucial, and that calls for experienced care about

When you can not figure out why your car makes a strange noise, you take it to a mechanic.