A High-Efficiency Dual-Band Linear-to-Circular Polarization Converter Based on Rectangular-Slot Reflective Metasurface

A this article, a novel and high-efficiency dual-wideband linear-to-circular polarization conversion based on a rectangular-slot reflective metasurface is anticipated, one that can convert linearly polarized (LP) electromagnetic waves into right- and left-hand circularly polarized waves in two non-adjacent frequency bands. The converter is an orthotropic design, with a pair of mutually orthogonal symmetric axes (u and v) along orientations tilted at 45 degrees to the y-axis. The simulated results indicate that the dual-wideband circularly polarized wave is achieved under a y-polarized an electromagnetic (EM) incidence wave over the bands of 16.49-23.54 GHz and 26.44-34.56 GHz with 3 dB axial ratio relative bandwidths of 35.23% and 26.62%, respectively, and a polarization conversion ratio (PCR) in excess of 99%. A detailed mathematical investigation is proposed to determine the fundamental factor causing the dual-wideband linear-to-circular polarization conversion. The phase difference (Delta phi(uv)) between r(uu) and r(vv) under u- and v- polarized incident waves is +/- 90 degrees, and it entirely determines the 3 dB reflected wave axial ratio. Any reflective converter can work efficiently as a linear-to-circular polarization conversion if the phase difference (Delta phi(uu)) is close to +/- 90 degrees.

Automated summary

This article introduces a novel dual-wideband linear-to-circular polarization converter, which can efficiently convert polarization in two non-adjacent frequency bands. A detailed mathematical investigation is conducted to determine the impact of the phase difference on the conversion effect.