[SOLVED] How to get frequency response from LTSpice?

[GMSong]

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.

 

[Audioguru]

I do it like this:

 

[frankrose]

How many points did you sweep the AC analysis? Probably not 0, but it is not visible.
PMOS Vgs is very low, even it is in subthreshold region. Especially compared to NMOS Vgs, which seems too high. Are you sure the transistors are in normal DC operating point?

 

[GMSong]

I do it like this:

what is your point? Adding .lib ?

 

[Audioguru]

Didn't you notice that I programmed my "AC Analysis" as ".ac oct 10 10 1Gig"?