Single-layer Prephased 1-bit Metasurface Using True-time Delay for Symmetric Beam Suppression

A single-layer prephased 1-blt metasurface for symmetric beam suppression under normally incident plane wave is proposed. By introducing true-time delay-based unit cells, the single-layer prephased metasurface is designed for millimeter-wave (mmWave) wireless systems. Compared with conventional designs, the proposed design resolves the inherent problem of single-beam patterns on 1-bit reflective metasurfaces under normally incident plane waves based on a very simple single-layer design. The proposed metasurface exhibits excellent performance, including low sidelobe level and accurate beam direction from 38GHz to 42GHz, which stands an attractive candidate for 5G mmWave applications.

I. Introduction

Recently, the programmable metasurface has been regarded as a promising scheme for achieving high spectrum and energy efficiency for mmWave MIMO wireless system [1]. A well-designed metasurface could achieve independent con-trol of polarization, amplitude and phase of electromagnetic waves with high efficiency and low complexity, and then reconfigure the wireless propagation environment [1], [2]. Many programmable metasurfaces have been proposed and demonstrated for beam-scaning [3]–[6].