Dual-band Polarizing Screen Based on Self-Supported Metallic Structures

A metallic periodic screen is here proposed that allows for dual-band operation and polarization conversion. The unit-cell structure is monolithic and three-dimensional, and it consists of a section of metallic waveguide loaded with perforations at its lateral walls. The geometry of the unit cell allows for independent control of incident fields with horizontal or vertical orientation. This feature is employed to manipulate the polarization of the illuminating wave. An equivalent circuit is proposed in order to model the cell behavior. Three design examples are proposed with different polarization conversion capabilities. One of the examples concerns a dual-band polarizer providing orthogonal sense of circular polarization at each of the bands. Such a design is manufactured and some preliminary measurements are shown in order to validate the proposed concept.