Airy Beam Dispersion in Near-Field Wideband Terahertz Communications
For terahertz communication systems, this work addresses the challenge of frequency-dependent beam dispersion in Airy beams, which is critical for near-field wideband applications.
The paper derives a closed-form expression for Airy beam trajectory dispersion in near-field wideband terahertz communications and proposes a true-time-delay-assisted beamforming structure to control it, enabling either sensing-oriented scanning or reliable communication.
This letter investigates Airy beam dispersion in near-field wideband terahertz communications. Unlike conventional focusing beams, whose dispersion mainly appears as focal-point migration, Airy beams exhibit frequency-dependent shifts of both the reference focusing point and the self-bending main-lobe trajectory. Based on the Fresnel diffraction integral, a closed-form trajectory expression is derived to characterize the dispersion behavior across subcarriers. Furthermore, a true-time-delay (TTD)-assisted Airy beamforming structure is developed to actively control the trajectory dispersion. By properly designing the time delay parameters, the proposed scheme can either generate frequency-dependent curved trajectory clusters for sensing-oriented scanning or suppress trajectory drift for reliable communication.