thermal noise

[as2717@sussex.ac.uk]

hello, i wanted to know about the noise ratio parameter in the thermal noise component. So, is it SNR, and fo rthat 20 value is really good.  or  is it just noise ratio so it means just noise without any signal, and higher the value worser the case. what do u mean by that? i m confused i dk which value to enter. pls help

[OEryashar]

Hello. Let's clarify the confusion for you.

SNR is not typically used as a parameter for individual components like thermal noise components because it describes the overall signal quality in a system rather than the noise contribution of a single component. Instead, the Noise Factor and Noise Figure are used to evaluate how much a specific component degrades the SNR, which is more relevant for assessing the component's performance in terms of noise.

• If the parameter is expressed in dB, you are dealing with the Noise Figure (NF).
• If the parameter is a linear ratio (not in dB), it is the Noise Factor (F).

Noise Factor (F): This is defined as the ratio of the input signal-to-noise ratio (SNR) to the output SNR. It is a linear ratio and is always greater than 1, as devices add noise to the signal.

Noise Figure (NF): This is the noise factor expressed in decibels (dB). It provides a more intuitive understanding of the noise performance of a device. The formula for converting noise factor to noise figure is:

[ NF = 10 \log_{10}(F) ]

Thus, the noise figure is simply the logarithmic representation of the noise factor.

I hope this helps!