Transparent Metasurface for Generating Microwave Vortex Beams with Cross-Polarization Conversion

Area of Science:

• Electromagnetic Metasurfaces
• Wave Polarization
• Orbital Angular Momentum

Background:

• Metasurfaces offer advanced control over electromagnetic (EM) wave properties.
• Generating cross-polarized waves and vortex beams simultaneously presents a significant challenge.

Purpose of the Study:

• To propose and demonstrate finite metasurface designs for dual-functionality: cross-polarization conversion and vortex beam generation.
• To achieve precise control over the orbital angular momentum (OAM) orders of generated beams.

Main Methods:

• Design and simulation of finite metasurface structures.
• Implementation of specific transmission phase distribution schemes.
• Experimental verification of simulated performance at 5.14 GHz.

Main Results:

• Metasurfaces successfully converted incident EM waves to their cross-polarization.
• Generated vortex beams with controllable OAM orders (l = +1, +2, -1, -2).
• Achieved low transmission loss (< 0.5 dB) and high cross-polarization purity (co-polarization level < -10 dB).

Conclusions:

• The proposed metasurface designs effectively achieve simultaneous cross-polarization conversion and vortex beam generation.
• Measurement results validate the simulation, confirming the dual-functionality and performance of the metasurfaces.
• These findings open avenues for advanced EM wave manipulation applications.