Parasitic strip dipoles to suppress grating lobes in a waveguide transverse slot array

A parasitic strip dipole array is proposed to suppress the grating lobes in a waveguide broad wall transverse slot array. A parametric study is conducted to see the variation of coupled excitation coefficients on a waveguide broad wall transverse slot and on a parasitic strip dipole in half space by using the method of moments (MoM). Dipole parameters are optimized for the best possible case of grating lobe suppression while all slots are excited with the same magnitude of a constant magnetic current. It is found from analysis that the grating lobes of 0 dB can be suppressed down to -15 dB in the presence of the parasitic dipole array.