
I am simulating the Common source amplifier circuit with current mirror. I wanted to see the frequency reponse of this circuit. And I got the constant value as you see the upper graph.

I have finally noitced if I change the value the parastic properties at Input Voltage Source, It shows the curve similar as I expected.
I want to ask you I'm on a right way to do AC simulation, And How should I set the parasitic properties. Thank you.