Generation and Focusing of Orbital Angular Momentum Based on Polarized Reflectarray at Microwave Frequency

Abstract

A novel polarized reflectarray is designed, fabricated, and experimentally characterized to show its flexibility and efficiency to control wave generation and focusing of orbital angular momentum (OAM) vortices with desirable OAM modes in the microwave frequency regime. In order to rigorously study the generation and focusing of OAM, a versatile analytical theory is proposed to theoretically study the compensation phase of reflectarray. Two prototypes of microwave reflectarrays are fabricated and experimentally characterized at 12 GHz: one for generation and one for focusing of OAM-carrying beams. Compared with the OAM-generating reflectarray, the reflectarray for focusing OAM vortex can significantly reduce the beam diameter, and this can further improve the transmission efficiency of the OAM vortex beams. We also show that the numerical and experimental results agree very well. The proposed design method and reflectarrays may spur the development of new efficient approaches to generate and focus OAM vortex waves for applications to microwave wireless communications.

3D-Printed Graphene-Based Bow-Tie Microstrip Antenna Design and Analysis for Ultra-Wideband Applications

“…Various techniques are used in antenna reconstruction methods. Some researchers use localized active components that allow changing half-point current or impedance lines [21], others apply mechanical remodeling in the antenna [22], and still, other researchers apply configurations using substrates with tunable properties [23]. Again, some techniques go the way of reconfiguring power supply networks or opting for excitation antenna arrays [24].…”

Multiple Orbital Angular Momentum Beams with High‐Purity of Transmission‐Coding Metasurface

“…It also has significant advantages of low profile, low cost, and ease of fabrication. [17][18][19][20][21] Therefore, metasurfaces can provide a new way to generate OAM beam. Recently, to easily realize OAM in microwave frequency, metasurfaces have been demonstrated by a series of experiments.…”

Suspended Metasurface for Broadband High-Efficiency Vortex Beam Generation

“…The foundation of these applications is the vortex beam source. Various methods have been proposed to generate vortex beams, such as antenna arrays [6,12], spiral phase plates [13,14], q-plates [15,16], holographic diffraction gratings [17], reflect arrays [18][19][20], metasurfaces [21][22][23][24][25][26][27][28][29], and so on. Almost all methods, apart from the antenna arrays approach, are centered on introducing OAM to the impinging wave, which involves applying the vortex phase to the incident waves, which can be expressed by the term exp(ilΦ), where Φ is the azimuthal angle and l is the OAM order.…”