Experimental Realization of Sub-THz Circularly Polarized Antenna Based on Metasurface Superstrate at 300 GHz

Area of Science:

• Electromagnetics and Applied Physics
• Antenna Theory and Design
• Metamaterials and Metasurfaces

Background:

• Advancements in wireless communication systems, particularly for 6G, necessitate antennas capable of high gain and specific polarization characteristics at sub-terahertz frequencies.
• Traditional antenna designs often face challenges in achieving low profile, high gain, and circular polarization simultaneously, especially at higher frequencies.
• Metasurfaces offer a promising avenue for manipulating electromagnetic waves, enabling novel antenna functionalities and performance enhancements.

Purpose of the Study:

• To present a low-profile, fully metallic, high-gain, circularly polarized resonant cavity antenna.
• To introduce a novel single-layer metasurface acting as a superstrate for polarization conversion and gain enhancement.
• To demonstrate the feasibility of using low-cost laser cutting brass technology for sub-terahertz antenna fabrication.

Main Methods:

• Design of a resonant cavity antenna incorporating a metasurface superstrate composed of hexagonal and octagonal radiating apertures.
• Utilizing laser cutting brass technology for the fabrication of the metallic metasurface and antenna structure.
• Characterization of the antenna prototype's performance, including gain, directivity, and polarization, at sub-terahertz frequencies.

Main Results:

• The proposed antenna prototype exhibits a low-profile planar metallic structure with dimensions of 2.6λ0×2.6λ0×1.24λ0.
• Experimental validation confirmed the antenna's capability to provide left-handed circularly polarized (LHCP) radiation.
• A measured LHCP gain of 16.2 dBic and directivity of 16.7 dBic were achieved at 302 GHz.

Conclusions:

• The developed circularly polarized resonant cavity antenna, with its metasurface superstrate, successfully achieves high gain and desired polarization at sub-terahertz frequencies.
• The proposed design and fabrication method using laser cutting brass technology offer a cost-effective solution for sub-terahertz antenna development.
• This antenna technology holds significant potential for future 6G wireless communication systems requiring efficient sub-terahertz operation.