Untilted Narrow-Wall Slots Excited by Parasitic Dipoles in Groove Gap Waveguide Technology

This work describes a new way to excite untilted slots in the narrow wall of a rectangular waveguide. The radiating structure consists of an inclined parasitic dipole located within the waveguide, parallel to narrow wall, and close to the untilted slot. Furthermore, the rectangular waveguide is advantageously replaced by a groove gap waveguide so that nonwraparound resonant slots can be used. The concept is discussed in detail and demonstrated experimentally through a linear array.