An efficient cost effective wide-angle metasurface-based linear and circular polarization converter for X-, Ku- and K-band applications

A highly efficient metasurface-based polarization converter is proposed for X-band (8.2–12.4 GHz), Ku-band (12.4–18.0 GHz) and K-band (18.0–27.0 GHz) frequency ranges. It provides a left-handed circular polarization in the X- and K-bands for a y-polarized incident plane wave in 10.85–11.05 GHz and 21.85–27.40 GHz frequency ranges. At the same time, the proposed design provides a left-handed circular polarization capability and has a linear polarization conversion ratio (PCR) greater than 97% in the frequency range of 12.35–17.8 GHz (Ku-band) for a y-polarized or a right-handed circularly-polarized incident wave. The proposed design produces a PCR value not less than 80% for incidence angles up to 50 degrees under oblique incidence. In addition, it is cost effective because it uses a relatively cheaper FR4 substrate material (1.6 mm) in its construction. For validation of the designed converter fabricated by the traditional board-circuit manufacturing method, we performed free-space measurements over 10–18 GHz frequency range. It is observed that measured co- and cross-polarized reflection coefficients are close to those simulated by the CST Microwave Studio — a full 3D electromagnetic simulation program. The feasibility of the designed converter for reduction radar cross section applications is also investigated. When compared with similar converter designs in the literature, it is noted that our proposed design works much more efficiently in the Ku-band with a high PCR value and oblique angle resistance performance (wide-angle independence). It also provides an efficient circular polarization conversion performance over a wider spectrum (X-, Ku- and K-bands).