Anomalous Reflection or Refraction Based on Transmissive Metagratings with Few Meta-Atoms

We propose the design of transmissive printed circuit board (PCB) metagratings with few number of meta-atoms to achieve extreme-angle anomalous reflection or refraction under normal incidence. Based on this, two metagrating prototypes with 70° anomalous reflection and 80° anomalous refraction under normal incidence are designed. The simulation results show a highly efficient extreme beam deflection, which can be a good alternative for future beamforming applications.