Low-Profile Reflective Surface for Multi-Band Linear-to-Linear and Linear-to-Circular Polarization Conversion

This paper proposes a thin multiband reflective polarization converter surface capable of transforming a linearly polarized (LP) incident electromagnetic (EM) wave into its orthogonal LP reflection wave in frequency bands of 8.14-8.25 GHz, 10.23-10.60 GHz, 13.90-14.08 GHz and 16.59-16.71 GHz, while, it reflects a circularly polarized (CP) wave in frequency bands of 7.8-8.10 GHz, 8.32-10.04 GHz, 10.80-13.75 GHz, 14.19-14.53 GHz, 16.22-16.52 GHz, and 16.77-17.18 GHz. The proposed unit cell of the periodic structure comprises slotted semicircles backed by a metallic ground plane and demonstrates considerable stability across all frequency bands, even under oblique incidence within an angle limit of 75°. Moreover, the proposed polarizer features a facile structure and manufacturing process, requiring only a single substrate layer without incorporating any via holes. A sample prototype consisting of $30\times 30$ unit cells was fabricated and tested, validating our design and simulations.