High‐Resolution Phase‐Magnitude‐Decoupled Information Metasurface for Complex Beamforming and Dual Channel 16QAM Secure Communication

Abstract Information metasurfaces have attracted considerable attention due to their remarkable ability to tailor electromagnetic (EM) waves flexibly. However, it is still challenging to achieve high‐resolution phase‐magnitude‐decoupled modulations with high integration and more degrees of freedom in 2D. In this work, a low‐profile phase‐magnitude‐decoupled information metasurface (PMDIM) is proposed that enables independent and high‐resolution controls of both phase and magnitude. By precisely applying different bias voltages to two groups of PIN diodes in the PMDIM unit cell, 2‐bit phase responses and continuous magnitude control ranging from 0.2 to 1 across wide bandwidth are achieved in unit‐by‐unit manner, offering 2D capability for EM manipulations. For validation, PMDIM is combined with carefully optimized phase‐magnitude coding sequences to realize two functions: complex beamforming and dual‐channel 16QAM secure communication. The first function includes single‐beam steering with low sidelobes, dual‐beam steering with power allocation, and multi‐beam steering; while the second function enhances the capacity and physical layer security of wireless systems. Measured results demonstrate excellent performance of PMDIM, showing significant potentials in modern radar and wireless communications.