Feko planar antenna feed

Hi, in Feko I would like to feed a planar antenna like a bow-tie sitting in a finite thickness substrate. I get errors at the beginning of the simulation either if I use edge port or wire port, basically the problem is that since the thickness of my metallization is infinitesimal the port actually is inside the dielectric of the substrate. How should I properly feed a planar bow-tie or a spiral antenna ?