Linear-to-Circular Polarization Transmission Converter Exploiting Meandered Metallic Slots

A novel wideband linear-to-circular polarization transmission converter composed by a cascade of two identical fully metallic frequency selective surfaces (FSSs) separated by an air gap is presented. The adoption of meandered slots patterned on a metallic layer, along with an interwoven FSS unit cell geometry, allows achieving up to 25% of 3 dB axial ratio bandwidth for a normally impinging plane wave. Moreover, by exploiting the FSS unit cell compactness, the converter provides a prominent robustness to oblique incidence, and it is therefore suitable to be employed in radomes and dichroics. As a proof of concept, a prototype of the proposed converter is manufactured and tested for assessing the design approach.