Fig. 1. Flowchart of algorithm

Fig. 2. Metasurface array schematic diagram

Fig. 3. Amplitude-frequency characteristics of units. (a) Amplitude of reflection; (b) phase difference

Fig. 4. Arrangement and characteristics of metasurface structures. (a) 2×2 subarray; (b) 4×4 subarray; (c) energy diagram of 2×2 subarray; (d) energy diagram of 4×4 subarray; (e) far-field scattering diagram of 2×2 subarray; (f) far-field scattering diagram of 4×4 subarray

Fig. 5. Monostatic RCS and reduction of different subarrays under vertical incidence conditions. (a) Monostatic RCS; (b) monostatic RCS reduction

Fig. 6. Bistatic scattering pattern of metasurface and metal plate at three frequency points at vertical incidence. (a)(d) 0.6 THz; (b)(e) 0.8 THz; (c)(f) 1.0 THz

Fig. 7. Scattering characteristics of metasurface array and metal plate at three frequency points when the reflected signal is incident vertically on XOZ plane. (a)(d) 0.6 THz; (b)(e) 0.8 THz; (c)(f) 1.0 THz

Fig. 8. Monostatic RCS and reduction of 4×4 subarray under oblique incidence. (a) Monostatic RCS; (b) monostatic RCS reduction

Fig. 9. Bistatic scattering pattern under oblique incidence at 0.6 THz. (a)(d) θ=15°; (b)(e) θ=30°; (c)(f) θ=45°