Space-Energy Digital-Coding Metasurface Based on an Active Amplifier

Power amplifiers display some interesting physical phenomena, such as nonreciprocity, but their characteristics have not been fully explored. In this study of the detailed relationship between supply power and amplification, the authors combine a coding metasurface with active amplifiers to realize arbitrary editing of the spatial distribution of a propagating wave's energy. With this metasurface, the energy in space of linearly polarized microwaves can be amplified or reduced at will by controlling the voltage.