Design of a Wideband Linear-to-Circular Polarizing Reflector for Ka-band Satellite Applications

This contribution presents a low-profile linear-to-circular polarizing reflector with wideband operation in Ka-band. The polarizing cell consists of three parallel dipoles placed with 45 degrees slant with respect to the direction of the incident linearly polarized field. The lengths of the dipoles are adjusted cell by cell through a dual-frequency optimization process, which accounts for the real incidence angles on each cell. A 25x25 cm flat polarizing reflector prototype has been fabricated and tested to validate the concept. The measured axial ratio is lower than 1.8 dB within the 19-30 GHz band (a relative bandwidth of 45%), and good matching with the simulations is obtained. The proposed polarizing reflector has applications in novel multibeam antenna configurations for Ka-band satellites.