Fig. 1. Polarization converter based on Miura origami can achieve multiple functional control of EM waves. First, in different folding states of origami, the polarization converter operates at different frequencies. In addition, by adjusting the folding angle of the origami structure, linear-to-linear and linear-to-circular polarization converters can be realized under the incidence of linear polarization waves, respectively.

Fig. 2. (a) Simulation setting of planar origami polarization converter (θ=0°). (b) Simulation setting of nonplanar origami polarization converter (θ≠0°). (c) Structural parameters of Miura origami substrate. (d) Dimension parameters of metallic split ring.

Fig. 3. (a) Simulated reflection spectra of the origami polarization converter. The surface current distributions on metallic parts under y-polarization incidence: (b) θ=15°, (c) θ=35°, and (d) θ=55°.

Fig. 4. (a) Sketch of the polarization azimuth angle α and the ellipticity angle β. (b) Co- and cross-polarized reflection amplitudes and phase difference between them under y- polarized wave incidence. The folding angle θ changes from 15° to 75° (f=3.1  GHz, ψ=45°). (c) Calculated azimuth angle α and the ellipticity angle β at different folding angles. (d) Polarization ellipses of the reflected wave at different folding angles (75°, 65°, 55°, 45°, 30°, and 15°).

Fig. 5. (a) When the folding angle θ=15°, the co-polarized reflection amplitudes and phases at 3.1 GHz under x- and y-polarized wave incidence. Current distributions on the surface of the metallic split ring at folding angle 15° (f=3.1  GHz), under two linearly polarized incident waves: (b) x-polarization incidence, (c) y-polarization incidence. (d) When the folding angle θ=75°, the co-polarized reflection amplitudes and phases at 3.1 GHz under x- and y-polarized wave incidence. Current distributions on the surface of the metallic split ring at folding angle 75° (f=3.1  GHz), under two linearly polarized incident waves: (e) x-polarization incidence, (f) y-polarization incidence.

Fig. 6. (a) Measurement experimental setup in microwave anechoic chamber. (b) Measured and simulated reflection spectra of the origami polarization converter under different folding states (θ=15°, 30°, and 55°). (c) When the folding angle θ=15°, the measured co-polarized reflection amplitudes and phases at 3.1 GHz under x- and y-polarized wave incidence. (d) When the folding angle θ=75°, the measured co-polarized reflection amplitudes and phases at 3.1 GHz under x- and y-polarized wave incidence.