Parameters and Measurement Techniques of Reconfigurable Intelligent Surfaces.

Area of Science:

• Electromagnetics and Wireless Communications
• Metamaterials and Surface Engineering

Background:

• Reconfigurable intelligent surfaces (RIS) are crucial for future wireless systems, enabling wave manipulation for enhanced performance.
• Existing RIS technologies face challenges in cost, spectral efficiency, energy efficiency, and smart environment integration for beyond-5G/6G.
• Polarization-related losses can degrade the performance of current wireless communication systems.

Purpose of the Study:

• To review existing RIS measurement techniques.
• To propose a novel, low-cost, polarization-independent RIS.
• To present a parameter measurement technique for the proposed RIS.

Main Methods:

• Literature review of current RIS measurement techniques.
• Design of a single-layer RIS using a low-cost FR4 substrate (1.6 mm height) operating in the sub-6 GHz band (3.5 GHz central frequency).
• Fabrication and laboratory measurement of reflection coefficients for a 10x10 unit cell array of the proposed RIS.

Main Results:

• A novel polarization-independent RIS structure was successfully designed and proposed.
• The proposed RIS utilizes a low-cost FR4 substrate and operates at 3.5 GHz.
• Experimental measurement of reflection coefficients validated the design's performance.

Conclusions:

• The proposed RIS design overcomes polarization-related losses, enhancing wireless communication efficiency.
• The low-cost, single-layer, polarization-independent RIS is a promising technology for future smart wireless environments.
• The presented measurement technique is suitable for characterizing the proposed RIS.