use of vector network analyzer

I have used vector network analyzer to test micro strip antenna. S11, smith chart and VSWR. May I know what any other measurements can be carried out?

In fact using a VNA you can measure the most important characteristic of the antenna: the Gain.
For this you need a reference antenna connected to one port of the analyzer, and the DUT antenna connected to the second port.
Measuring the S21 is giving you a relative information about gain of your antenna.
Replacing the DUT antenna with a dipole you get a relative antenna gain information in dBd.