Slot coupling and scattering

The moment method using global sinusoidal expansion and testing functions has been used for the analysis of scattering from a single slot in a screen as well as a slot backed by a waveguide. The method is basically the same as that used for slot admittance calculations. The results agree with the radar cross section in the (Babinet) equivalent strip dipole case. Slot fields have been computed for several cases including oblique incidence. Finite wall thickness is also treated. Bistatic scattering from a slot loaded with a waveguide section on the rear side was studied. The coupling to the waveguide modes in the waveguide was also obtained. Oblique incidence is shown to produce an asymmetrical field distribution which results in nonsymmetric coupling to the waveguide modes as well as a nonsymmetric bistatic cross section distribution.<>