Beam Steering by Two Vertically Faced Metasurfaces Using Polarization-Free Unit Cells with Three Operating Modes

TL;DR

This paper presents a novel metasurface unit cell with three polarization modes for beam steering on nonflat surfaces, demonstrating effective absorption and phase shift capabilities through simulations.

Contribution

It introduces a polarization-free unit cell with three modes and analyzes two vertically faced metasurfaces, expanding beam steering applications to curved or multi-sided surfaces.

Findings

Achieves -10 dB absorption in absorption mode

Provides 180-degree phase shift in reflection mode

No quantized beam observed with one-bit phase shift

Abstract

Intelligent reflecting surfaces (IRS) are valuable tools for enhancing the intelligence of the propagation environment. They have the ability to direct EM Waves to a specific user through beamforming. A significant number of passive elements are integrated into metasurfaces, allowing for their incorporation onto various surfaces such as walls and buildings. In certain situations, metasurfaces may need to be installed on surfaces that are not flat, such as surfaces with curves or surfaces with two sides. In this work, a unit cell with three polarization modes, consisting of absorption, reflection, and a 1-bit phase shift, is designed and investigated. The unit cell in the nonplanar metasurface is composed of two vertical surfaces. A mathematical model is used to analyze two vertically-faced metasurfaces. The results include S parameter values and full structure. It is demonstrated that both absorption reflection mode and phase shift mode are achieved within a specific frequency band. The simulations demonstrate that an appropriate absorption level, reaching -10 dB, is achieved in absorption mode. In reflection mode, a 180-degree phase shift is achieved within the same frequency band. Reports on the radiation pattern of two vertically faced structures indicate that there is no quantized beam when there is a one-bit phase shift.