The Far-/Near-Field Beam Squint and Solutions for THz Intelligent Reflecting Surface Communications

Terahertz (THz) and intelligent reflecting surface (IRS) have been regarded as two promising technologies to improve the capacity coverage for future 6G networks. Generally, IRS is usually equipped with large-scale elements when implemented at THz frequency. In this case, near-field model beam squint should be considered. Therefore, in paper, we investigate far-field problems communications first time. The channel models are constructed based on different electromagnetic radiation characteristics. Next, analyze its effect gain cascaded base station (BS)-IRS-user model, then case studied. To overcome effects, propose apply delay adjustable metasurface IRS, develop a scheme of optimizing phase shifts time delays elements, which effectively eliminates loss caused by squint. Finally, simulations conducted demonstrate effectiveness our proposed schemes combating