FEKO__EME reflection problem. Cute "Blondie" needs help ;)

Hello to everyone!

Recently I have started new thread concerning trihedral corner reflector simulation in FEKO, but unfortunately, nobody answered me. And my main question is steel opened. So, in attachment there is screen shoot of my trying to simulate a metal plane and plane wave, normally falling on it.
Could you explain me please, where is error? The plane wave passes through metal plane (the same picture is if the material is a perfect electric conductor) and reflects only from ground plane (reflection coefficient approximation).
If I remove the ground plane, then the plane wave at the level z=0 reflects and refracts (on what - I even do not know) so, that both parts are equal.
Its all wrong, I know.
In the pictures below E-field is shown.

Element type is metallic triangles.
And if I delete the plane, nothing will be calculated.

Heh... *surely* with this revised subject line you'll shake some FEKO experts out of the woodwork to help! :)

With my (marginal) background of RCS and my (non-existent) experience with FEKO, the first thought that springs to mind is that the diffraction effects you're seeing are entirely explicable if you're illuminating the reflector with a plane wave... a plane wave extends to infinity normal to the direction of propagation. As such, your reflector intercepts a portion of the wavefront (and reflects it), with another portion being diffracted around the edges (and a yet third component passing by unaffected). Knowing absolutely nothing about FEKO (CST is my weapon of choice :) - does it have calculation boundary conditions (such as E=0) that would be "reflecting" your incident plane wave and clouding your RCS simulations?

Good luck!

thylacine1975, thank you very much! Your idea is grate! I'll look over excitation settings more careful right now!