Path Loss Modeling of RFID Backscatter Channels With Reconfigurable
Intelligent Surface: Experimental Validation
Abstract
In the realm of radio frequency identification (RFID) technology, the
integration of reconfigurable intelligent surfaces (RISs) has opened up
new possibilities for real-time remote data capturing and seamless
connectivity. By manipulating the electromagnetic properties of the
environment, RIS enables the control of electromagnetic wave propagation
and allows for virtual line-of-sight (LOS) in cases where physical LOS
is blocked. This has tremendous implications for the future of RFID
applications, particularly with the emergence of chipless RFID
technology. In this regard, this paper develops free-space path loss
models for RIS-assisted RFID wireless communications. The proposed
models in this study have taken into account several crucial physical
factors, including tag radar cross-section (RCS), the physical
properties of the RIS, and the near-field/far-field effects of the RIS.
To further validate the theoretical findings, we have conducted
experimental measurements using a fabricated RIS. Numerical simulations
were also utilized to validate the models and verify our findings. The
channel measurements have demonstrated good agreement with the proposed
path loss models, further bolstering the potential of RIS-assisted RFID
wireless communications.