Generation of Multi-Mode OAM Waves Through 1-Bit Direct-Radiating Programmable Metasurfaces

A direct-radiating programmable metasurfaces is presented for generating multi-mode OAM beams. The proposed direct-radiating metasurfaces is composed of 1-bit electronically reconfigurable units, which are integrated with two PIN diodes in the radiation layer for current inversion. Compared with the traditional transmissive or reflective metasurfaces, the feeder source is integrated into the infrastructure of the metasurfaces for a lower profile.