Anisotropic programmable metasurface beam splitter based on diode real-time control

we propose an anisotropic programmable coding metasurface, which is composed of digital coding elements integrated with PIN diode. The "0″ and "1″ states of the diode are controlled in real time by external voltages, and a single metasurface unit is controlled by the FPGA (Field Programmable Gate Array). Due to the polarization-sensitive characteristics, it is not only possible to switch the polarization states in the orthogonal two directions separately, but also to realize the remote scattering control at any angle by means of convolution coding. The metasurface can be converted on polarization (linear polarization or circular polarization) by means of real-time coded modulation. We further experimentally prepared a diode based programmable coding metasurface and measured the angle of far-field scattering using a microwave test system. The independent polarization wavefront control greatly enhances the channel capacity of metasurface, and programmable metasurface has a higher degree of freedom when multifunction modulation is realized.