A Low-Profile Tri-Functional Metasurface Toward Polarization Conversions and Absorption

The integration of multiple functions on a miniaturized device can significantly reduce the complexity of a system and is considered one of the emerging trends. Metasurfaces have emerged as powerful tools for integrating multiple functions in a single device. A tri-functional reflective type metasurface for simultaneous linear to cross-polarization conversion (LP-CPC), conversion of linear to circular polarization (LP-CP), and absorption of the incident wave is demonstrated in this letter. The unit cell consists of a circular split ring and four L-shaped metal strips on the top of a metal-backed 1.6 mm thick FR-4 substrate. The proposed structure yields a wide band LP-CPC over (12.76 to 24.86) GHz and dual band LP-CP conversions for frequency bands (11.5 to 12.3) GHz and (25.88 to 29.65) GHz. Moreover, the proposed design exhibits more than 90% absorptance at 31.18 GHz; thereby making the metasurface trifunctional. The simulation results of the designed metasurface are simultaneously validated by an equivalent circuit model and experimental characterizations of the fabricated prototype. The proposed tri-functional metasurface offers a promising platform for advanced, diversified applications in radar, communication systems, and sensing technologies.