DESIGN AND THEORY OF SLOT ARRAYS FED BY SINGLE-RIDGE RECTANGULAR WAVEGUIDE (ANTENNA, PHASED)

When slots are arranged in arrays, mutual coupling between slots cannot be ignored if a good match and pattern are to be obtained. A theory has been developed for slot arrays in single-ridge rectangular waveguide so that the length and offset of every slot in the array can be determined for a specified aperture distribution and input match in the presence of mutual coupling. The electromagnetic field in single-ridge waveguide is obtained from an integral-eigenvalue equation which is solved numerically by the Ritz-Galerkin method. A general relation between slot voltage and forward- and backward-scattering off the slot, including mutual coupling effects, is developed with the aid of the reciprocity theorem. Finally, formulas are derived for a slot admittance in the array environment. These formulas result in a design procedure. A two-by-eight longitudinal slot array has been constructed to test the theory.