Orthogonal anisotropy-programmable metasurface for simultaneous polarization and deflection control of reflected waves

Coding metasurfaces offer dynamic electromagnetic wave control, but existing multi-polarization designs often exhibit narrow bandwidths or limited polarization states. This work proposes a broadband orthogonal anisotropy-programmable metasurface operating within 6.0–9.5 GHz, enabling multi-polarization manipulation and efficient circular-to-linear polarization conversion. By introducing isotropic metallic structures and tunable PIN diodes, the unit cell can achieve switchable isotropic and anisotropic states. This enables 1-bit phase encoding for co-polarized reflected waves of arbitrary polarization, derived from the orthogonal x - and y -polarization basis. Conversely, the 1-bit phase encoded cross-polarized reflection, resulting from the unit cell’s anisotropy, is suitable for circularly polarized (CP) and 45° polarized incident waves. Key performance metrics include a 180° phase difference between ON/OFF states and insertion losses under 3 dB across the bandwidth. Furthermore, adjusting the coding sequence under circularly polarized wave incidence generates x - or y -polarized reflected waves with robust beam-steering capabilities. Measurement results validate the beam deflection performance under both reflection modes, showing excellent agreement with simulations through periodic coding adjustments. This reconfigurable framework for simultaneous polarization and deflection manipulation is crucial for next-generation wireless communication and radar.