I have been trying to construct a circuit for a week and a half now and i cannot understand why it can't seem to work. I have to design a CMOS diffretial pair with a current mirror that is not the tricky part. The hard part is that i have to use a unipolar supply to operate it. can some one help me out here? Your help would be greatly appreciated.

 

This looks like homework.
Show us what you've done so far.
There's nothing difficult about using a single supply with a current-mirror circuit.
They do not need two voltages.

 

Divide the supply voltage by 2 and change the labels on the drawing. For instance, 0, +10V becomes: +5v, -5V

 

http://www.aicdesign.org/scnotes06.html

 

Is this homework for school?