Diffraction of a Gaussian beam wave by finite periodic slots in a parallel-plate waveguide

The diffraction problem of a Gaussian beam by finite number of periodic slo ts in a parallel-plate waveguide filled with a homogeneous dielectric is co nsidered. The integrodifferential equation for the unknown equivalent surfa ce magnetic current density over the slots is derived and solved by the met hod of moments (piecewise sinusoidal Galerkin method). From some theoretica l results for the angular diffraction pattern, the present geometry is obse rved to simulate well the previous rectangular groove geometry from the vie wpoint of scattering behaviour. In addition, two types (resonance and non-r esonance types) of Bragg blazing phenomena are discussed. Simultaneous Brag g and off-Bragg blazing is also demonstrated.