Design of Reconfigurable Intelligent Metasurface with Swallowtail-Shaped Element for Flexible Dual-Beam Scanning

In this paper, a dual-beam 2-bit Reconfigurable Intelligent Metasurface (RIS) is proposed for dual-zone coverage of mobile communication systems. The proposed intelligent metasurface can achieve arbitrary dual-beam scanning within $\theta \leq 60^{\circ}$, including both the symmetrical and asymmetrical dual beam scanning. Moreover, the designed metasurface has good directionality and its main beam gain remains relatively uniform within the scanning range, which is a promising candidate for dual-zone radio wave coverage, indoor wireless communications, dual-target satellite communications, and other dual-target wireless applications.