1-bit Reconfigurable Unit Cell for Direct-radiating Programable Metasurfaces

An electronically reconfigurable unit with 1-bit phase resolution is presented for direct-radiating programable metasurfaces in X-band. Compared with the traditional transmissive or reflective metasurfaces, the feeder source is integrated into the unit infrastructure of the direct-radiating metasurfaces for a lower profile. The phase difference of the two states maintains at around 180° with very small deviation within the operation band. The simulated results verify that the proposed reconfigurable direct-radiating unit can achieve good 1-bit phase tuning with minimum return losses and efficient radiations.