{{mainpage|[[Radiation Pattern Above A Half Space Medium]]}}
[[Image:FDTD133.png|thumb|200px|Far Field Background Medium dialog.]]
As mentioned earlier when discussing boundary conditions and computational domain, you can use CPML boundary conditions with zero offsets to model a structure with infinite lateral extents. At the end of the FDTD simulation, the far fields are calculated using the near-field-to-far-field transformation. This calculation requires the dyadic Green's function of the background structure. By default, the FDTD engine uses the free space dyadic Green's function for the far field calculation. In general, the [[FDTD Module]] features dyadic Green's functions for four scenarios: