Tunable Multibeam Holographic Metasurface Antenna

A metasurface beam-steering antenna at microwaves is proposed in this letter, which is designed according to holographic theory and has the ability to create multibeam radiation patterns with independent control of the individual beam direction. The holographic design approach of the modulated impedance surface follows the methodology of linear superposition of individual field patterns for each beam. The unit cell of the proposed antenna is tuned with a low-loss varactor diode, and its dispersion diagram is obtained with a transverse resonance technique. A novel multibeam antenna fed by a single source is designed with independent beam steering of each beam at around 7.2 GHz. The dual-beam antenna exhibits an average of 11.6 dBi of realized gain for each independent beam.