Experimental Demonstration of Wireless Transmission Using Airy Beams in Sub-THz Band

Abstract

The use of sub-THz bands makes it possible to take advantage of physical properties of electromagnetic waves that have not been actively exploited to date. Shortened radio wavelengths in sub-THz bands and large-diameter antennas extend the near-field range to hundreds of meters and enable more precise beam manipulation using electromagnetic near-field phenomena. In this work, we investigated the Airy beam, whose main lobe power distribution follows a curved trajectory along its propagation. We first explain the main physical properties of the Airy beam, which include the curved trajectory of the main lobe power distribution, asymmetric sidelobe distribution, and self-healing. Then, we perform experimental verifications to confirm such physical properties. Specifically, we experimentally demonstrate a method to control the curved trajectories, which has not been explicitly demonstrated using sub-THz bands in the literature so far. In addition, we experimentally perform the transmission of four different streams using four Airy beams, taking advantage of the fact that low-interference transmission of multiple streams is possible thanks to the asymmetric sidelobe distribution properties of Airy beams. Our findings show that the total transmission rate exceeds 400 Gb/s, indicating that Airy beams can be utilized for high-capacity wireless transmission in sub-THz bands. Finally, we experimentally validate the self-healing property of the Airy beam through wireless transmission over a wireless link that is partially blocked by an obstacle. This provides new use cases for sub-THz bands, such as obstacle avoidance. Our theoretical and experimental research on Airy beams will leverage the diverse physical properties of electromagnetic waves to provide expanded and versatile uses in wireless communications.