“…A wide variety of functionalities has been tailored from metasurfaces, including wavefronts manipulation, − polarization conversion and control, − holographic imaging, − vortex beam generation, , and antennas and lenses, − to name a few. In this context, geometric phase, also referred to as Pancharatnam–Berry (PB) metasurfaces, and, more precisely, passive metasurfaces combining both geometric and propagation phases, are exploited to achieve different functionalities under different incident polarized waves. − Recently, metasurfaces integrating several switchable electromagnetic functionalities into a single device have attracted enormous interest. − On the basis of the digital coding metamaterials concept, coding metasurfaces have also been proposed to achieve more than one functionality in a single device. , Meanwhile, metasurfaces incorporating reconfigurability mechanisms, such as p–i–n diodes or varactor diodes, graphene, and insulator-to-metal transition materials, have also been proposed for dynamically switchable functionalities. − Space–time modulated digital coding metasurfaces incorporating p–i–n diodes and controlled by a field-programmable gate array (FPGA) have shown the possibility to simultaneously manipulate electromagnetic waves in both spatial and frequency domains and to dynamically control nonreciprocal effects. , …”