We present a staircase-shaped transmissive metasurface for linear-to-circular (LTC) polarization conversion, achieving an axial ratio bandwidth (ARBW) of about 41% and covering the entire X band (8–12 GHz). Unlike designs based on discrete resonators, the proposed structure is based on meander-line conductive elements with electrical continuity across unit cells. This promotes distributed surface currents that contribute to a broader operational bandwidth. The metasurface operates in transmission mode and enables switching between right- and left-handed circular polarization (RHCP/LHCP) through a simple 90° mechanical rotation. In addition, the LTC response remains robust under oblique incidence, with the ARBW remaining above 33% for incidence angles up to 45∘. Experimental results are in very good agreement with simulations and confirm stable handedness switching. Owing to its geometrical nature, the operating frequency can be easily scaled by adjusting the unit-cell dimensions. As a proof of concept, a Ku-band (12–18 GHz) design achieving comparable broadband performance is also demonstrated. These results highlight the potential of continuous, distributed-current-based metasurfaces for compact and broadband polarization control in microwave systems.
Molina-Cuberos et al. (Thu,) studied this question.