A Compact, High Efficiency FR-4 and Aluminum based Triple-Band Polarization Conversion Metasurface with Jerusalem-Cross Resonator Element for C, X and Ku band Applications

Existing multi-band polarization conversion metasurfaces often face a trade-off among high polarization conversion ratio (PCR), broad operating bandwidth, compact size, and angular stability, which limits their practical use in microwave systems such as satellite links, radar platforms, antenna polarization controllers, and polarization-sensitive wireless communication devices operating across the C-, X-, and Ku-bands. To address this challenge, a triple-band polarization conversion metasurface (PCM) is presented, comprising a Jerusalem-cross resonator enclosed within a square split-ring resonator (SRR) on an FR-4 substrate with aluminum metallization. The metasurface demonstrates four prominent plasmonic resonances at 5.51, 8.24, 13.95, and 17.2 GHz, where the PCR approaches unity (≈100%). Consequently, the PCM achieves efficient cross-polarization conversion across three distinct frequency bands, 5.29–5.87 GHz, 7.34–9.23 GHz, and 12.66–17.7 GHz, with fractional bandwidths of 10.39%, 22.81%, and 33.2%, respectively. The PCM exhibits symmetric behavior for both x- and y-polarized incident waves and maintains stable polarization conversion performance with only minor variations up to an incidence angle of 40 ∘ , attributable to its sub-wavelength cell size, geometric configuration, and careful selection of substrate and metal thickness ensuring stable electromagnetic performance and fabrication robustness. Furthermore, analysis of the axial ratio and the phase difference between reflection coefficients confirms efficient linear-to-circular polarization transformation. These characteristics make the proposed PCM a strong candidate for compact multi-band polarization-control functions in satellite communication payloads, radar cross-polarization management, dual-polarized antenna subsystems, and microwave sensing or wireless links requiring stable polarization conversion.