A Wideband Polarization Converter With High Efficiency for Millimeter-Wave 5G Applications

This letter presents an innovative, low profile, wideband linear-to-linear cross-polarization converter metasurface (MS) tailored for millimeter-wave (mmW) 5G applications. The designed polarization converting metasurface (PCMS) efficiently transforms incident linearly polarized electromagnetic waves into their orthogonal counterparts. Throughout its operational bandwidth spanning from 24.6 GHz to 76.8 GHz, the proposed MS maintains a polarization conversion ratio (PCR) exceeding 90%. Notably, this bandwidth extends over 52.2 GHz, resulting in a fractional bandwidth of 103%. The broad operational range owes its success to induced surface currents, which engender multiple resonances and enhance PCR. The substrate dimensions measure 0.02λ<sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">o</sub> × 0.02λ<sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"/> (2.6 mm × 2.6 mm) with a thickness of 0.08λ<sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">o</sub> (1 mm), where <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$\lambda _{\mathrm{o}}$</tex-math></inline-formula> represents the maximum wavelength at the lowest frequency within the operating band. The proposed PCMS effectively covers the 5G New Radio mmW frequency range 2 band from 24.25 GHz to 71.0 GHz. A prototype is fabricated and subjected to experimental testing, revealing closely aligned simulated and measured results. Monostatic radar cross section (RCS) reduction analysis of the proposed PCMS is also studied with reference to perfect electric conductor. This proposed MS holds significant promise across various domains, including satellite and 5G communication systems, reflector antenna design, RCS reduction techniques, and beamforming applications.