Fig. 1. Schematic diagram of functions and meta-atoms of the designed multi-channel focusing and holographic metasurfaces.

Fig. 2. Properties of the designed meta-atoms for different structure sizes and incidence angles under LP incidence: reflection amplitude and phase spectra for different structure sizes (a) u1 and (b) x1 under x-LP incidence, (c) amplitude and (d) phase for different incidence angles under x-LP incidence, and (e) amplitude and (f) phase for different incidence angles under y-LP incidence.

Fig. 3. The meta-atom library is composed of four meta-atoms with a 180° phase interval for LP incidence at different frequencies: (a) f1=8.0  GHz and (b) f2=15.0  GHz.

Fig. 4. Electric field distributions of the meta-atoms at different layers and frequencies under LP incidence: (a) larger cross-shaped structure and (b) smaller cross-shaped structure at 8.0 GHz, (c) larger cross-shaped structure and (d) smaller cross-shaped structure at 15.0 GHz.

Fig. 5. Phase distributions of the metalens for different polarization incidences and operation frequencies: (a) x-LP and (b) y-LP at 8.0 GHz, (c) x-LP and (d) y-LP at 15.0 GHz.

Fig. 6. Electric field distributions of the focal points at different polarization incidences and operation frequencies: (a) x-LP, (b) y-LP, and (c) 45° LP at 8.0 GHz, and (d) x-LP, (e) y-LP, and (f) 45° LP at 15.0 GHz.

Fig. 7. Electric field distributions on the focusing plane at the frequency ranges from 7.0 GHz to 8.0 GHz and from 13.0 GHz to 17.0 GHz for different polarization incidences: (a) x-LP incidence and (b) y-LP incidence.

Fig. 8. Target images and simulated images on the imaging plane for different polarization incidences and frequencies: (a) x-LP and (b) y-LP at 8.0 GHz, (c) x-LP and (d) y-LP at 15.0 GHz.

Fig. 9. Electric field distributions on the imaging plane at two frequency ranges from 7.5 GHz to 8.3 GHz and from 13.0 GHz to 17.0 GHz for different incidences: (a) x-LP incidence and (b) y-LP incidence.

Fig. 10. Fabricated sample and measurement environment: (a) optical image of the fabricated focusing metasurface and (b) measurement environment in the microwave anechoic chamber.

Fig. 11. Simulated and measured results of the fabricated focusing metasurface for different polarization incidences and frequencies: (a) x-LP and (b) y-LP at 8.0 GHz, (c) x-LP and (d) y-LP at 15.0 GHz.