Polarization spatial diversity and multiplexing MIMO surface enabled by graphene for terahertz communications.

Area of Science:

• Physics
• Electrical Engineering
• Materials Science

Background:

• Terahertz (THz) frequency band offers abundant spectrum for high-data-rate, low-latency communication.
• Multiple-Input Multiple-Output (MIMO) is vital for THz communication, requiring synchronous and non-correlated channels.
• Existing THz communication systems face challenges in channel synchronization and crosstalk.

Purpose of the Study:

• To propose and demonstrate a graphene-based polarization spatial diversity and multiplexing MIMO surface (PDM-MIMOS).
• To achieve synchronous modulation and crosstalk-free reception for dual-polarized THz channels.
• To enhance communication quality, data rates, and reliability in THz communication systems.

Main Methods:

• Design and fabrication of a 2x2 metasurface array for PDM-MIMOS using graphene.
• Implementation of a continuous THz wave communication system incorporating the PDM-MIMOS.
• Experimental evaluation of modulation cut-off frequency, spatial diversity, and multiplexing capabilities.
• Comparative analysis of THz communication and visible light communication under adverse weather conditions.

Main Results:

• The PDM-MIMOS enables synchronous modulation of dual-polarized channels with a cut-off frequency up to 30 kHz.
• Demonstrated spatial diversity and multiplexing, improving communication quality and data rates.
• THz communication using PDM-MIMOS showed 19.4 times higher reliability than visible light communication in adverse weather.

Conclusions:

• The proposed PDM-MIMOS is effective for enhancing THz communication performance.
• Graphene-based metasurfaces offer a viable solution for compact, dual-polarized THz modulators.
• This technology has significant potential for THz communication, detection, and imaging applications.