I am trying to wrap my mind around very small signals; what they mean, and how to amplify them.
For example, here is a screenshot from my cell phone. Notice the signal level received is -97dBm. Apparently, this is pretty standard for a cell phone signal.
So, by my calcs, -97dBm is approximately 0.1 picoWatt of power. That seems like a really small amount of power. And I mean really small!
I tend to think in terms of my college physics lab whereby we had 5v supplying 1A of current into a light bulb. Or something like this, from what I remember. When that power comes down from the receive antenna and into the amplifier, what does the amplifier "see"? A very small voltage potential? It just seems so small that I'm having a hard time grasping the concept.
Now, how does it get amplified? I was looking at some simple low noise amplifiers (LNA), NXP BGU7003, to make a simple circuit that amplifies the signal. I was planning on using the app note for this chip as an example.
Is there a discreet component way this is done? Where would I look to get more insight into the circuit design of something like this? Wouldn't a tiny power RF signal like this get "lost" in the noise of an LNA?
I'm just so perplexed by this. So any help/insight is most appreciated.