impulse response in HFSS

Hello, please it is possible to find the impulse response of a telecommunication system in HFSS
Thanks in advance

Yes, by performing a transient simulation.

can you explain me more indication plz ; for example for the gain of antennaa result--> create far field report-->gain.. so what dos mean transient simulation

I don't believe gain is defined for non-steady-state excitations. I would assume that the IEEE has, however, defined many systems and quantities for impulse responses - perhaps a literature review would be in order.

Good Luck