I've been casually aware that signal gain can be added in "stages" but never really considered how that might actually work in practice. And it seems that some RF amplifiers really prefer to only "sample" the input signal rather than use any of its incoming power, e.g. some QRP amps I've seen even attenuate the input signal before using it to drive their output signal.
But for example I happened to recently see a classified listing for a Mirage B-5016-G amplifier which is sold as taking "50 watts in, 160 watts out". Does an amp like that simply allow high powered input signals, but still just dissipate/attenuate them down to essentially nothing before using only the underlying signal to gate the output current?
Or are there transistors where the input power must be relatively high in order to control an even higher power output?