A Linear to Circular Polarization Converter Based on Substrate Integrated Waveguide Cavities

This paper presents a polarization converter that a linearly polarized incident wave can be converted into a circularly polarized wave. The proposed structure is composed of a two-dimensional periodic arrangement of dielectric-filled substrate integrated waveguide cavities (SIWC) in unit-cell of which double-layer slot frequency selective surface (FSS) cascaded with dielectric layers. Through the coupling of the input and output waves with slots on the layers, two linearly polarized outgoing waves with orthogonal polarization can be transmitted. When the two orthogonally polarized components are combined and adjusted with equivalent amplitude and 90° phase difference, they can be synthesized into circularly polarized wave.