How to simulate differential amp and calculate its noise figure using HSpice?

I have several questions about differential amp:

1. How to calculate its noise figure?
2. how can i simulate the differential amp using Hspice? (such as gain, s-parameters, zin and zout)

Hi..
try to visit this site, also see razavi books of CMOS ANalog circuit design on EDA books forum.

http://www.ece.cmu.edu/~ee762/hspice...001_2-213.html

It depends, if you want with opamps or with discrete components.
my old differential amplifier article might be a starting place, it doesn't cover everything however, might be interesting.