Common Gate Amplifier
This is an amplifier where the input is applied to the Source and output is collected across the Drain.
The Gate is connected to a dc voltage called bias which ensures the device is operating properly.
The figures 10 (a) and (b) show two different circuits depicting the operation of Common Gate Amplifier / connection
Figure 10 (a) Common Gate with Direct Coupling (b) Common Gate with Capacitive Coupling
In Figure 10(b), the MOS is biased by a constant current source and the signal is capacitively coupled to the input of the circuit