Microwave applicator employing a broadside slot radiator

Claim 1

In a microwave energy applicator for treating materials with microwave energy, broadside radiator means disposed for radiating microwave energy into the material to be treated, the improvement wherein, said microwave radiator means includes a hollow elongated waveguide structure having an array of coupling slots communicating through the wall of said waveguide structure, said slots being disposed in the side of said waveguide structure facing the material to be treated, each of said slots being elongated in a direction parallel to the longitudinal axis of said waveguide structure, said slots being disposed along a line substantially parallel to the longitudinal axis of said waveguide structure, said slots being resonant at approximately the operating frequency of the applicator, said slots being axially spaced apart along said waveguide structure on their centers by approximately one half a guide wavelength within said waveguide structure at the operating frequency of the applicator, slot loading means disposed adjacent said slots and disposed projecting into said waveguide from alternate sides of adjacent slots for coupling microwave energy from said waveguide through said slots in an in-phase relation to obtain a broadside antenna radiator, and means for conveying material to be treated through the broadside lobe of microwave energy radiated from said radiator along a path having a substantial component normal to the longitudinal axis of said waveguide structure.