A study on a waveguide slot antenna with dielectric covers

A narrow slot in the broad wall of a rectangular waveguide is analyzed using the moment method which takes account of both the waveguide and dielectric covers. The presence of a dielectric sheet in a waveguide slot can alter the characteristics of the slot antenna and considerably affect the mutual coupling in the slot array. In order to analyze the effect of the waveguide slot position and shape, the Green function is derived for the waveguide and dielectrics regions respectively. The resonant length of the slot has a large variation due to the frequency of the field and the thickness of dielectric slab when the slot is tilted and positioned far from the center of the waveguide. The result of the proposed analysis leads to a new slot antenna design that has the designed beam shape and controllable gain and bandwidth