Alignment-free twisted-split-ring metasurface on single substrate with 2π phase range for linearly polarized...

Area of Science:

• Electromagnetics
• Metamaterials
• Wireless Communication

Background:

• Next-generation mobile systems require advanced manipulation of sub-terahertz wave propagation for high-speed, large-capacity communication.
• Existing methods for wave manipulation face challenges in efficiency and industrial applicability.

Purpose of the Study:

• To propose and validate a novel split-ring resonator (SRR) based metasurface unit cell for manipulating linearly polarized sub-terahertz waves.
• To achieve efficient polarization conversion and 2π phase designability for mobile communication applications.

Main Methods:

• Designing a split-ring resonator (SRR) structure with a 90° twisted gap for cross-polarized wave manipulation.
• Fabricating a complementary pattern of the unit cell and a metasurface lens with binary phase profiles.
• Experimentally verifying the performance of the fabricated structures, including polarization conversion efficiency and lens functionalities.

Main Results:

• Achieved linear polarization conversion efficiencies of -2 dB (with backside polarizer) and -0.2 dB (with two polarizers).
• Measured peak conversion efficiency exceeding -1 dB with a backside polarizer on a single substrate.
• Demonstrated metasurface lenses with focusing, deflection, and collimation capabilities, exhibiting a lens gain of 20.8 dB.

Conclusions:

• The proposed SRR metasurface offers independent control over phase designability and efficiency gain, enabling alignment-free characteristics beneficial for industrial applications.
• The metasurface lens demonstrates easy fabrication and implementation, with potential for dynamic control when integrated with active devices.
• The simple design methodology, relying on twist direction and gap capacitance, facilitates widespread adoption in future communication systems.