> the system noise is dominated by the first amplifier stage.
In radio receiver design you have an LNA, low noise amplifier, as the first stage. It's designed for low noise and to be linear. Idea is take the energy from the antenna and amplify it with as little noise and cross modulation as possible[1].
[1] If the amp is non linear you end up folding out of band signals into your band of interest.
In radio receiver design you have an LNA, low noise amplifier, as the first stage. It's designed for low noise and to be linear. Idea is take the energy from the antenna and amplify it with as little noise and cross modulation as possible[1].
[1] If the amp is non linear you end up folding out of band signals into your band of interest.