Don't ask for something you can do yourself.Would you be able to give me a sketch of the characteristic curve Vin vs. Vo in order i can understand where to place the bias point?
Thank you for your answer , but i was talking about the voltage characteristic of the buffer not of the single mosfet. for the curve of the whole buffer there is no sense to plot vin vs id is easier to plot Vo vs Vin (which is the curve i was asking you) and check where the derivative is maximum dvo/dvin there is the place at maximum gain. Actually I already did it but I wanted to compare with your suggestion and discuss on it.Don't ask for something you can do yourself.
Simulate the Vin versus Id for the transistors you have.
From that you can tell how to bias them.
Generally you want a few tens of milliamps of bias.
I know what you are talking about. But, as has been pointed out, the buffer won't work as shown. You can't plot what you want. Trying to get the characteristics of a circuit that doesn't work is pointless.Thank you for your answer , but i was talking about the voltage characteristic of the buffer not of the single mosfet. for the curve of the whole buffer there is no sense to plot vin vs id is easier to plot Vo vs Vin (which is the curve i was asking you) and check where the derivative is maximum dvo/dvin there is the place at maximum gain. Actually I already did it but I wanted to compare with your suggestion and discuss on it.