2-Bit Ultrathin Amplitude-Modulated Coding Metasurfaces with Inserted Chip Resistors

Introduction of digital coding metasurface encoded with predesigned coding sequences has rapidly improved the design efficiency and broadened the applications to real-time controls. Different from the previous researches on coding metasurfaces in terms of phase distributions, we propose an ultrathin amplitude-modulated coding metasurface inserted with chip resistors at 5.76 GHz and 9.6 GHz. The proposed coding metasurfaces are composed of split-ring resonators (SRR) and inserted chip resistors with certain coding sequences for generating amplitude-modulated radiation patterns, while keeping other states unchanged. By arranging the relevant coding sequences, we can obtain almost continuous amplitude controls instead of redesigning the structure.