A highly efficient low-cost reflective anisotropic metasurface for linear to linearly cross- and circular-polarization conversion

In this research, a highly efficient single-layer reflective polarization converter based on anisotropic metasurface is proposed for microwave communications. The periodic design works in a dual-operation mode as a half-wave plate (cross-polarizer) and a quarter-wave plate (circular-polarizer) over multiple frequency bands. The unit-cell is comprised of coupled D-shaped resonators printed on a low-cost FR-4 substrate offering cross-polarization conversion (above -3 dB) over three frequency bands (6.45-6.87, 9.94-11.34, and 15.99-18.60 GHz) with cross conversion efficiency higher than 90%. Moreover, the proposed metasurface can also work as a linear to circular polarizer over three bands (6.0-6.25, 7.35-9.05, and 12.28-15.18 GHz). The design is further shown to be angularly stable for incidence angles up to 30 degrees. The proposed design has been validated experimentally after fabrication.