Excitation of untilted narrow-wall slot in groove gap waveguide by using a parasitic dipole

This paper describes a new way to excite untilted slots in the narrow wall of a rectangular waveguide. The mechanism basically relies on an inclined parasitic dipole located within the waveguide, close to the slot and parallel to waveguide's narrow wall. The proposal is completed with a discussion of the convenience of using a groove gap waveguide in connection with this radiating element to significantly simplify fabrication process of slotted waveguide arrays.