Low-profile linear polarization conversion metasurfaces using degenerate modes for high selectivity

In this paper, two ultrathin polarization conversion metasurfaces (PCMs) were designedfor linear polarization of electromagnetic waves. A method of controlling degenerate modes was applied for enhanced selectivity. The surface resonator is a square patch etched with orthogonal cross-slots. Adjustment of the cross-slot size is beneficial as it introduces a perturbation factor and controls the splitting of the degenerate modes. The constructed dual-mode single-band and four-mode dual-band PCMs with different pairs of degenerate modes can efficiently reflect linear polarized waves to the orthogonal polarization counterpart in the range of 5.89-6.4 GHz and 5.88-6.30 GHz/8.19-8.59 GHz, respectively. Current distribution and an equivalent circuit model were studied to reveal the polarization conversion mechanism. Finally, experiments were implemented to verify the near unity cross-polarization conversion efficiency at the corresponding bands. Given the PCM's advanced performance of low profile and high selectivity, it has great potential applications in controlling the polarization state of microwaves.

Automated summary

In this paper, two ultrathin polarization conversion metasurfaces (PCMs) were designed to convert linear polarized waves to orthogonal polarization counterpart. The degenerate modes were controlled to enhance selectivity. The PCM demonstrated efficient cross-polarization conversion in specific frequency ranges, making it a promising technology for controlling the polarization state of microwaves.