Fig. 1. Schematic of the designed metasurface. (a) Schematic of 6×6 array; (b) schematic of unit cell; (c) resonance cell of top metal; (d) bottom feeder layer

Fig. 2. Equivalent circuit models of BA591 at different states

Fig. 3. Reflection coefficients and PCR of designed metasurface when the diodes are in on-state or off-state. (a) Reflection coefficients in on-state; (b) PCR in on-state; (c) reflection coefficients in off-state; (d) PCR in off-state

Fig. 4. Analysis of polarization conversion principle. (a) Schematic of polarization conversion; (b) reflection coefficients and phase difference under the excitation of E_iu and E_iv,respectively; reflection phases changed with the length l₂ under the excitation of (c) E_iv and (d) E_iu,respectively; reflection phases changed with the length l₁ under the excitation of (e) E_iv and (f) E_iu,respectively

Fig. 5. Surface current distributions at different resonance frequencies when PIN diodes are in on-state. (a) 4.34 GHz; (b) 5.67 GHz; (c) 7.26 GHz

Fig. 6. PCR at different incident angles

Fig. 7. Measured results. (a) Photo of the sample; (b) measured environment; measured reflection coefficients and PCR for the diodes in (c) on-state and (d) off-state; (e) measured PCR at different incident angles