Commonly, a common drain amplifier is recognized as a buffer or simply a supply follower. It can be Usually applied for the output stage on the LNA structure. This amplifier has fewer output impedance. So, it can provide excellent output impedance matching. Normally, an LNA is used in all receivers https://archerfbvpj.thekatyblog.com/35093124/rumored-buzz-on-pin-diode-switch