Hybrid-Modulated Programmable Metasurface with Angular Stability for Precise Electromagnetic Wave Manipulation

Reconfigurable metasurfaces have emerged as a pivotal technology for next generation communications, offering substantial benefits in optimizing signal propagation paths. However, current reconfigurable metasurface designs often neglect the angular performance, a critical factor since electromagnetic (EM) waves usually illuminate with oblique angles in practical applications. Here, a 2-bit phase modulating programmable metasurface with angular stability is proposed. By integrating metallic wall vias, multiple reflection interference is effectively suppressed, mitigating coupling between adjacent meta-atoms under oblique incidence, thereby realizing stable EM responses under broad incident angles from 0 degrees to 60 degrees. Additionally, by adopting a hybrid PIN-varactor diode modulating mechanism, the frequency reconfigurability is integrated to address the bandwidth limitations typically encountered in multi-bit metasurfaces. As a proof-of-concept, the capability of precise beam deflection under oblique incidence is demonstrated by numerical simulations and experimental measurements, which is implemented in N78 and N79 bands, two representative frequency bands in the fifth-generation communications. The proposed programmable metasurface not only facilitates the dynamic spectrum management but also ensures reliable signal transmission in dynamic scenarios such as urban outdoor non-line-of-sight communications and drone swarm coordination, enabling it as a promising candidate for next-generation wireless system architectures.