Using ADS , how to find the Band Width of Amplifier Using Predefined BW function

Using Agilent Advanced Design System (ADS), How to find the Band Width (BW) of the Amplifier Using Predefined Function.

The data display function for bandwidth calculation is discussed here:
http://www.keysight.com/owc_discussi...D=66959𐖏

As you said link, I have gone through that link. They have given many following equations to find the Band Width.

1) bandwidth_func(db(s11),1)
2) bandwidth_funct(dbzin(s11)),1)
3) fc= center_freq(db(s21),0.0000000001)
I messed with the above equations. Which one I have to use. Which one will give the correct bandwidth measurement of the Amplifier.
Is there any other equation to accurate measurement of Band Width in ADS.

These are just examples that show how to use the bandwidth function. It depends how you define bandwith for your amplifier (which parameter to evaluate and how much reduction from the peak value you accept).