Simultaneous Full‐Space Beamforming and Scattering Reduction by a Broadband Reflection‐Transmission Integrated Metasurface

ABSTRACT Full‐space metasurfaces have shown remarkable capabilities in modulating electromagnetic (EM) waves in transmission and reflection spaces together, resulting in less EM resource wastage. However, the existing full‐space metasurfaces fall short in actual applications due to the narrow working band, complex structure, and poor confidentiality performance. In terms of functionality, most full‐space metasurfaces cannot achieve scattering reduction and full‐space beamforming simultaneously. Here, we propose a broadband metasurface capable of directional beam‐shaping in both reflection and transmission spaces while achieving 10 dB scattering reductions in the reflection space. The proposed meta‐unit consists of two gratings forming a “Fabry‐Perot‐like” cavity and a split ring resonator between them. In the working frequency band, altering the opening angle of the split ring allows for 1‐bit phase modulation of the transmitted and reflected waves under y‐polarized incidence. To illustrate the concept, we design two distinct transmission array antenna samples (000111… and 00001111…) that achieve full‐space dual‐beamforming and scattering reduction simultaneously from 11 to 19 GHz. The good agreement between measured and simulated results confirms the anticipated functions of the proposed metasurface.