DESIGN OF CROSS POLARIZATION CONVERSION OF METASURFACES

Abstract Polarization manipulation is a vital aspect of electromagnetic wave control, with significant applications in communication, radar, imaging, and sensing systems. Traditional methods, such as those based on the Faraday effect, suffer from bulkiness and limited bandwidth, motivating the exploration of metasurfaces for advanced polarization control. Metasurfaces, composed of subwavelength structures, offer compact, tunable platforms capable of converting polarization states dynamically, even under varying incident angles. This research proposes the design and optimization of metasurfaces for robust cross-polarization conversion, aiming to enhance performance across wide angular and frequency ranges.While conventional methods face challenges like narrow bandwidth and angle sensitivity, metasurfaces offer a compact and efficient alternative due to their subwavelength structure and tunability. This research employed CST Microwave Studio for numerical simulations, considering practical limitations in fabrication, material modeling, and experimental validation. The key objectives include designing metasurfaces for efficient polarization conversion, optimizing performance metrics such as polarization conversion ratio and reflection coefficients, and analyzing electric and current density distributions. The metasurface demonstrates nearly identical co- and cross polarized reflection coefficients when illuminated by x- or y-polarized incident waves, indicating strong polarization insensitivity and efficient conversion. Notably, the metasurface achieves near-perfect polarization conversion ratios (PCRs) at resonance frequencies of 5.49 GHz, 8.19 GHz, and 14.37 GHz, confirming its multi-band functionality. While effective under normal incidence, cross-polarization reflection increases at oblique angles (e.g., 6.6 GHz), revealing some sensitivity and energy loss under intermediate incident angles. These findings confirm the metasurface's potential for integration into modern wireless communication systems, offering compact, wideband, and efficient polarization manipulation across multiple frequencies. he designed metasurface proves to be an effective polarization converter, capable of transforming electromagnetic waves between horizontal and vertical polarizations with minimal energy loss. Unlike conventional antennas that suffer from polarization mismatch, the metasurface exhibits polarization insensitivity, ensuring consistent performance regardless of the incident field orientation. Future designs should focus on refining electric field distribution, surface currents, and current density to improve polarization conversion efficiency and minimize energy loss. 7