transfer function hfss

hi all:
In general, we make a single antenna model in HFSS firstly , and run HFSS to get the antenna's parameters . Then how to set in HFSS can we get the phase response or transfer function? since the transfer function should include two antennas , i think .
so , any one know it , please tell me your operation steps in HFSS and i will appreciate you very much.
best regards.
kaka