Full-duplex Reflective Beamsteering Metasurface Featuring Magnetless Nonreciprocal Amplification

Abstract Nonreciprocal radiation refers to electromagnetic wave radiation in which a structure provides different response under the change of the direction of the incident field. Modern wireless telecommunication systems demand versatile apparatuses which are capable of full-duplex nonreciprocal wave processing and amplification, especially in the reflective state. Here, we propose full-duplex reflective beamsteering metasurfaces for magnetless nonreciprocal wave amplification. To realize such a unique, extraordinary and versatile functionality, we propose a completely new architecture in which a chain of series cascaded radiating patches are integrated with nonreciprocal phase shifters, providing an efficient mechanism for wave reception, signal amplification, nonmagnetic nonreciprocal phase shifting and steerable wave reflection. Having accomplished all these functionalities in the reflective state, the metasurface represents a conspicuous apparatus for efficient, controllable and programmable wave engineering for wireless telecommunications. Such an ultrathin reflective metasurface can provide directive and diverse radiation beams, and steerable beams by simply changing the bias of the gradient active nonmagnetic nonreciprocal phase shifters. The proposed structure provides large wave amplification and is immune to undesired time harmonics, yielding a highly efficient full-duplex reflective beamsteering apparatus.