Study of a high gain radial line slot antenna in Ka-band for space uses

A slot array design for a very high gain of more than 44dBi RLSA was reported in this paper. A conventional slot array design procedure based on the Method of Moments (MoM) was still applied, but needed to modify in order to adapt with a very large number of radiating elements and a complex, multilayer structure of the substrate. A fast analysis method based on a simplified but reliable equivalent model of the multilayer waveguide was established to estimate the antenna performance. Finally, several RLSAs having φ = 900mm diameter were fabricated and characterized by the near field measurement. In the optimum case, a directivity of 48.3dBi correspond to 73% aperture efficiency was obtained at 31.9GHz, at which the measured gain was 44.6dBi.