Dual Band Transmissive Circular Polarizer Based on Metamaterial Split Ring Resonator

This paper presents a dual band transmissive circular polarizer based on metamaterial split ring resonator (SRR) to achieve asymmetric transmission of linear-to-circular polarized waves across dual frequency bands. The designed structure achieves right-handed circular polarization (RHCP) and left-handed circular polarization (LHCP) waves at 16.13–16.80 GHz and 16.90–17.24 GHz, respectively. Notably, the axial ratio bandwidths are 3.72% and 14.77% at the dual band frequencies. Moreover, 5×5 array has also been analyzed. The observed giant circular dichroism (CD) is explored through surface current distributions. These features make it highly suitable for advanced polarization conversion applications. Overall, the design achieves axial ratio (AR) bandwidth of 18.49% across the 12–18 GHz frequency range.