Ka band Radial-waveguide Slots Antenna Array with Flat-top Beam Radiation

For wireless power transmission systems in space applications, the volume and weight of equipments and the available input power must be strictly limited. To ensure effective wireless power transmission, it is necessary to operate wireless power transmission via millimeterwaves. To improve the efficiency of rectifying, it is hoped to obtain uniform power density distribution at the receiving end. Aiming at this problem, a Ka band radial-waveguide slots antenna array with flat-top beam radiation is proposed in this paper. By adjusting the amplitudes and phases of electric fields radiated from the slots on the radial-waveguide and the microstrips on the substrate, the flat-top beam radiation can be realized. At the same time, the structure of radial-waveguide is beneficial to reduce loss and improve radiation efficiency at millimeterwave band, and also can achieve a low profile antenna design.