A high-gain and high-efficiency single-layer slotted waveguide array for use in 22 GHz band for entrance radio relay system in mobile communications

The authors have developed low-profile single layer slotted waveguide arrays. For the high frequency applications, they paper demonstrate the excellent performance of these types of antennas designed for 22 GHz entrance radio relay systems. The structure of the single-layer slotted waveguide array is shown. The antenna consists of only two parts and can be fabricated by placing the slotted plate on the groove structure. The slotted plate can be made by printing technology while the groove structure can be made by die casting; it is suitable for mass production and costs reduction. The feed waveguide is placed perpendicularly in the same layer of the radiating waveguides and is a cascade of /spl pi/-junctions with an inductive wall. All the radiating waveguides are excited in phase since the guide wavelength in the feed waveguide is set to twice the width of the radiating waveguide including the wall thickness. They are excited in equal amplitude as well by controlling the width of the windows in the /spl pi/-junctions.