Ultra-thin reflective multifunctional polarization converter with nested circular ring-shaped metasurface-based for C- and X-band applications

This article presents a single-layer, ultra-thin and multifunctional polarization converter (PC) design using metasurface. The PC, which is proposed as a single layer, consists of a metal metasurface on the front side of a easily accessible FR-4 material and a metal termination on the back surface. The suggested PC features linear polarization (LP) characteristic within a frequency ranges of 5.21-5.41 GHz and 7.53-8.08 GHz in C-band, also 10.59-10.84 GHz in X-band under normal incidence. It indicates the conversion performance of linear polarization to circular polarization (LP-CP) that has the properties of left-handed circular polarization (LHCP) in frequency range of 5.74-7 GHz in C-band and right-handed circular polarization (RHCP) in frequency range of 8.63-10.15 GHz in X-band. Besides, the suggested PC provides more than 90% polarization conversion ratio (PCR) value in case of normal incidence (0?) and over 80% PCR value in case of oblique incidence up to 45?. Again, the suggested PC offers the same CP feature in two frequency regions where CP conversion takes place under normal incidence for angle of incidence up to 60?. A prototype of suggested PC was produced, measured, and a good match was found between the results simulated via a commercial electromagnetic (EM) simulation program. Finally, the performance of suggested design is compared with existing studies in literature with its high aspects. In this context, the suggested PC may be useful for C-and X-band applications due to its simple structure, ultra-thin and compactness, low-cost, and performance of LP and CP conversion under wide oblique angles.