Thank you so much for the reply. Yes, you are totally right I want to make an antenna. The cone-like structure is really close to the wafer and I have to make the cone act like an antenna with the highest directivity towards the silicon wafer and see how the wafer reacts (meaning the s11 parameter). But firstly I will be really glad if I can make the antenna work. Maybe somehow I need to simulate the nearfield of the antenna, but I don't know what excitation to use (wave port, lumped port, current, voltage, or anything else) nor what boundaries to apply. The only thing I know is that the signal should enter through the top of the cone (applied to the circle face on top of it) and that it is 9 GHz, and that the cone is made of gold surrounded by a box of air including both the cone and the silicon wafer in it.