Arrays of closely-spaced nonresonant slots

Slots laid broadside to each other exhibit mutual coupling of such magnitude that the design of practical linear arrays of such slots has hitherto been difficult, if not impossible. The technique presented here will produce arrays capable of generating pencil beams or shaped beams with controllable side-lobe level. A large number of slots per wavelength are used and the mutual-coupling effects are kept small by making the slots short compared to a half wavelength. Tests have shown that these arrays may be placed side by side without interaction, thus making it possible to construct a two-dimensional array.