steps to plot stability circle

Hi all

I am doing an assignment in LNA design. I was stucked up with drawing stability circle. I read the book RF circuit design by chris bowick. In that it was mentioned that to draw the stability circle find the center and radius of the circle with some formulas and to mark the center follow as if to plot the noraml reflection coefficient in the smith chart and draw the circle with radius ranging between 0 to 1 but my question is to

1) how to plot the center of the circle in the smith chart?
2) then what is the scale of the radius? I dont really understand how to take the scale of radius?

Reference : example 6.6 in the text book above mentioned

I really need some help to proceed further in my design.

Hi Santom
Check out following link for Bowick book.
http://rapidshare.com/files/14907230...750685182_.rar

Also Refer Gonzalez book.(Microwave Transistor Amplifiers)
This is Awesome book for making amplifiers.

Added after 43 seconds:

Use this software to plot circles.