hjee
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Posts: 2
Suwon, South Korea
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Basicly, it's better to know the noise model is input equivalent or output equivalent. Then you'd better to declare the match impedence R to generate the noise pwr 4kRT - which is also referred to source noise. noise factor = SNR|output / SNR|input noise figure(NF) = 10*log(noise factor) SNR|output = S|input * Gain^2 / N|input+N|amp_output SNR|input = S|input/N|input
=> noise factor = Gain^2*N|input / (N|input+N|amp_output)
Up to now, we can model or derive the output equivalent noise N|amp_output
At last, we can also derive the input equivalent noise, N|input = N|amp_output / Gain^2
Above is the basic noise modeling for LNA in RF receiver.
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