Q:

Biasing using a Current Source in NMOS Common Source Amplifier

I see that there are multiple ways to bias a simple Common Source NMOS transistor but I want to understand about biasing using current source.
I put up this circuit in SPICE:

The above is simple Common Source Amplifier biased with help of current source without a constant gate voltage. My first question is, "is this really biased with current source? or is it biased with -1.4V below the current source?" 
I called this "biasing using current source" because changing the current value changes the operating point and Source potential is not fixed (while operation).
Well, now arises an interesting observation. I see that this circuit amplifies the voltage variations at Gate (which is what i wanted). 
However, the source potential varies with gate. (acts as source follower).
But to amplify, shouldn't the source potential be fixed? Only then Gate-Source potential would vary and produce the output right? So, I wanted to know how current variation happens across the resistor to amplify the signal? (shouldn't the current just stay constant?)

A:

How are you measuring gain? You have to run AC analysis to measure gain. Also, connect the other end of the current source to ground. By the way, this circuit cannot have any gain at low frequencies because the current source acts as an AC open. Also, this is a biasing circuit and is not intended as a gain block.

