[HFSS] Antenna Measurement and Simulation

Hello,
if we measure antennas in the antenna chamber with vector-network-analyzer (VNA).
Let's say two identical antennas:
The measured S21 transmission parameter (divided by 2 and corrected for freespace loss) is available for each angle (azimuth, elevation).
How do I reproduce those results with HFSS.
Farfield result: dB(RealizedGain) is fine, how do I get the phase values?
Thank you.
-e

So, for the sake of completeness. I was wondering why there is no phase information for realized gain. Actually we now use realized gain plus Etheta (mag/phase) and Ephi (mag/phase) for further analysis.