Analysis and fabrication of millimeter-wave slotted waveguide array antennas

Two topics on slotted waveguide array antennas are described. First, a three-dimensional structure of a T-junction to feed a partially-dielectric-filled waveguide is decomposed into two two-dimensional problems uniform in the orthogonal directions to each other in order to reduce the calculation time. The partially-dielectric-filled waveguide reduces the equivalent dielectric constant and the transmission loss and realizes hard-walls in the side walls from practical point of view. Secondly, diffusion bonding of laminated metal thin plates is applied to a 60GHz double-layer waveguide slot array with fully corporate feed. The antenna gives more than 32dBi and 80% efficiency over about a 5GHz bandwidth in measurement.