I'm working with the AFE5818, which includes a Low Noise Amplifier (LNA), a Voltage-Controlled Attenuator (VCAT), and a Programmable Gain Amplifier (PGA). I'm curious why the signal chain is designed to first amplify (LNA), then attenuate (VCAT), and finally amplify again (PGA). Wouldn't this introduce additional noise? Why not integrate all functions into a single stage to avoid extra noise?
