Tri-band Linear to Circular Polarization Converter based on Transmissive Metasurfaces

Multi-band operation for terahertz wireless systems is a challenging problem. We propose a tri-band linear to circular polarization converter in the terahertz regime using metasurfaces in transmission modes. The converter is composed of bi-layered metasurfaces separated by a dielectric spacer. Three bands (0.54-0.804, 1.904-2.476, and 2.96-3.884 THz) of linear to circular polarization conversion (LCPC) are achieved due to the superposition of the two transmitted components with a near 90° phase difference. Idea is verified by HFSS and paves a way to the design of multi-band transmissive linear to circular polarization converter.