a Logic Behind the excitation inside Cylinder

Dear Friends,

I am dealing with the simulation of infinite extented dielectric cylinder. I have read some thesis about the simulation of dielectric cylinder and I have seen that teh excitation (planewave) is performed inside cylinder. I thought that one should have excite the cylinder from outside. I am wondering why the plane wave excitation is put inside cylinder in HFSS?

Already thank you very much for your interest...

best regards..

--->>> Right excitation

--->>> My excitation (Why it is not used)

http://www.ee.olemiss.edu/atef/journ...Dielectric.pdf