Multipole analysis of perforated metal-only surface for polarization-selective transmission and reflection beams

This article demonstrates polarization-selective transmission and reflection (PSTR) using a metallic surface periodically perforated with sub-wavelength rectangular apertures of different lengths and orientations. A theoretical study supported by rigorous multipole analysis shows that, with the proposed design, a polarization-dependent pseudo-anapole state can be realized, which results in reflection cancellation for one polarization and high reflection for the orthogonal polarization. To validate the proposed design, two array prototypes (prototypes I and II) have been fabricated from a thin stainless-steel sheet (0.1 mm thick) and measured. The first prototype (prototype I) shows the PSTR at 12.3 GHz. The second prototype (prototype II) exhibits the PSTR at three frequencies (9.96, 11.25, and 11.95 GHz). In addition, both array prototypes exhibit multiple transmission windows in their respective transmission spectra. The proposed designs may find applications in various bidirectional communication systems that require both transmitted and reflected beams.