Wideband OAM generator based on high order meta-frequency selective surface

A low profile wideband transmitarray for generating focusing orbital angular momentum (OAM) wave based on high order meta-frequency selective surface is proposed in this paper. The employed meta-FSS element with a fourth-order band-pass filter property, which exhibits the merit if low profile, high transmissivity and wide angular stability. A panel consisting of 17×17 elements is designed to generate +1 mode OAM wave at broadside direction. Simulated results show that the proposed structure can convert the incident spherical phase front into OAM beam helical phase distribution from 11.0 GHz to 13.0 GHz.