Fast multi-band antenna simulation HFSS

I am atrying to simulate a dual-band antenna in HFSS. The first band is (0.15-0.7)GHz, the second one is (2-7)GHz. The problem is that, if I take I take one simulation set-up the radiation box will be calculated for the lowest frequency (0.15GHz)and the simulation exceutes with an out of memory problem. Is there an easier way to solve this problem. Is there a way to add a diffrent radiation box for each setup in HFSS.

Regards,