LAUSR

Digital-coding metasurfaces provide a convenient method for designing metasurface-based functional devices. By delicately arranging the coding sequences, electromagnetic fields on the metasurfaces can be modulated for applications like wave-front engineering, amplitude controlling and polarization conversion. Theoretically, to fully realize arbitrary profiles for radiation patterns, both amplitude and phase modulations are needed for the responses of meta-atoms. Here, a method is proposed to generate multiple beams with arbitrary power intensity ratios using 2 bit amplitude and 2 bit phase digital-coding metasurfaces. A detailed process for designing the coding sequences is elaborated, and four-layer conformal square-loop meta-atoms are adopted to achieve 16 combinations of amplitude and phase codes. Two prototypes with dual beams of different radiation angles and power allocations are simulated, fabricated and measured. The experimental results match well with the predesigned expectations, which verifies the feasibility of the proposed method. It suggests that the digital-coding metasurface is a good candidate for multi-beam radiation pattern syntheses and is promising for various multi-functional telecommunication and radar applications.