Wideband and High-Efficiency Backscattering Enhancement Based on Origami Metasurface Retroreflector

An origami-based metasurface retroreflector is proposed to realize highly efficient wideband back reflection. The design integrates origami-based gradient phase arrays that are articulated at angles of $\boldsymbol {\alpha = 25^{\circ } }$ and $\boldsymbol {\beta = 45^{\circ } }$ and constitutes a $20\times 18$ array of resonant units. By morphing a 2-D surface into a quasi-planar configuration, the retroreflector significantly broadens its operational bandwidth and enhances backscattering capabilities. Simulations and experimental validations collectively demonstrate that the origami retroreflector provides a notable 21-dB enhancement in radar cross section (RCS) within the angular range of $ \boldsymbol {45^{\circ } \pm 4^{\circ } }$ . It exhibits a relative bandwidth of 18.87% under transverse electric (TE) polarization from 9.6 to 11.6 GHz and 15.81% under transverse magnetic (TM) polarization from 9.9 to 11.6 GHz. In addition, the retroreflector foldable nature allows for a substantial reduction in volume, reaching as low as 10% of its original size upon complete retraction. The proposed origami metasurface retroreflector exhibits potential applications in radar target detection, enemy identification, and maritime rescue due to its wideband RCS enhancement, lightweight structure, and foldable characteristics.