Post-wall waveguide slot array antennas

This paper presents the up-to-date results of the post-wall waveguide slot array antennas. The guide wavelength of post-wall waveguide is discussed as a function of the post diameter and the post spacing by solving an eigen-value problem. The efficiency of the post-wall waveguide fed parallel plate slot array antennas is presented as a function of the antenna size. The center-feed is proposed in the parallel-plate antenna to fix the main-beam direction and enhance the gain bandwidth. We describe the beam-switching antenna by integrating a Butler matrix with slot array antennas in a single-layer dielectric substrate.