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Static Reflective Surfaces for Improved Terahertz Coverage

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Abstract

LoS (Line of Sight) MIMO (Multiple Input Multiple Output) is considered the best way to deliver high-capacity channels for terahertz communications due to the severe attenuation suffered by reflected components. Unfortunately, terahertz links are easily blocked by any obstruction resulting in link breakage. Therefore, it is necessary to provide alternative paths via reflectors. A problem shared by LoS paths and reflected paths (via polished reflectors) is that the channel matrix is rank 1 in the far field. As a result, the achieved capacity is lower than what can theoretically be achieved in a rich multi-path environment. In this work, we simultaneously solve the channel rank problem and the coverage problem by using static reflective surfaces which provide limited scattering of the incident signal in a way that minimizes signal loss but provides multiple paths to the receiver with varying phase. We construct such a surface and characterize the received signal using a terahertz testbed. We show that using our surface, we can improve channel capacity for 2 × 2 LoS MIMO. We also develop a theoretical model for the received signal and show that the reflected capacity matches the measured capacity well.

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Data Availability

Availability of data and code: Our data is available at: http://web.cecs.pdx.edu/~singh/projects/thzmimo/Home.html and code is available upon request.

Notes

  1. We use the terms reflective element and metal strip interchangeably in this paper.

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Funding

This work was funded by the National Science Foundation under grant CNS-1910655.

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Authors and Affiliations

  1. Department of Electrical and Computer Engineering, Portland State University, Portland, OR, 97207, USA

    Thanh Le & Suresh Singh

  2. Department of Computer Science, Portland State University, Portland, OR, 97207, USA

    Suresh Singh

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  1. Thanh Le
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Contributions

The authors contributed equally to this work. T.L.: conducting experiments; performing analysis and modeling; writing, reviewing, and editing manuscripts. S.S.: funding acquisition; project administration and supervising; writing, reviewing, and editing manuscripts.

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Correspondence to Thanh Le.

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Le, T., Singh, S. Static Reflective Surfaces for Improved Terahertz Coverage. J Infrared Milli Terahz Waves 45, 466–485 (2024). https://doi.org/10.1007/s10762-024-00985-y

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