Huygens' Metasurfaces for Antenna Beamforming and Beamsteering

Huygens' metasurfaces provide a platform for realizing low-profile antennas without sophisticated feeding networks that increase power losses. In particular, they can synthesize radiating apertures by passively transforming the incident fields. In this paper, we summarize recent progress on the field of beam-forming and beamsteering with Huygens' metasurfaces. Several strategies to overcome the limitations posed by the passivity of Huygens' metasurfaces and to achieve arbitrary beamforming are explored. Furthermore, ways to integrate tunable metasurfaces with leaky-wave antennas are discussed with the purpose of obtaining steerable far-field patterns.