Scattering from a PEC plate in CST

Hi,

I tried to simulate the calssical problem of scatttering from a plate due to an incident plane wave on CST. I created a thin plate and defined the exciation as a plane wave. but couldn't get the expected current singularities near the edges that are parallel to the incident electric field, even after refining the mesh and using PBA and tetrahedral mesh. I need to know if this is a problem with CST that it cannot predict current singlarities or is it a problem of FDTD simulators.

Thanks for listening
BR
Adel_48