Information metasurfaces have attracted much attention in recent years due to the capability to link the physical world and information science. However, most of the current information metasurfaces are either phase-only coding or amplitude-only coding, limiting their functions and applications. Here, a broadband and programmable amplitude-phase-joint-coding (APJC) information metasurface is proposed and experimentally demonstrated, from which the phase and amplitude of reflected electromagnetic waves can be independently controlled by adjusting the bias voltage of PIN diode integrated in the meta-atom. In particular, the reflection amplitude can be continuously controlled from 0.1 to 0.9, and the reflection phase can be switched between two states with about 180° phase difference. Thus, the proposed metasurface is capable of realizing independent 1-bit or multibit amplitude coding and 1-bit phase coding, and both of them can be reprogrammed in real time in broad band from 8 to 13 GHz. The abilities of the programmable APJC information metasurface in manipulating the electromagnetic waves are demonstrated by both numerical simulations and experiments, including to suppress the sidelobes of scattering beam, generate the diffractive waves with arbitrary magnitudes, and so on. These results show unique advantages of APJC information metasurface in real-time independent controls of energy allocation and wavefront tailoring of the electromagnetic waves in a wide frequency band.
Keywords: amplitude; information metasurface; joint coding; phase; programmable.