Towards a Heuristic Path Loss Model for RIS Links

The continuously increasing demand for higher data rates drives the exploration of low terahertz (THz) frequency bands for mobile communications, leveraging their large available bandwidths. To reduce dependency on line-of-sight (LOS), the concept of reflective intelligent surfaces (RISs) has emerged as a promising technology. By reconfiguring the electromagnetic environment, RIS alters the channel, requiring novel approaches to model key parameters such as path gain. To address this, an approach based on the bistatic radar equation is proposed, which accounts for the altered path gain progression due to near field effects.