An Efficient Algorithm to Determine the Operational Range of Near-Field On-Body UHF RFID Systems

A new algorithm is proposed, leveraging a 3D multipole expansions of the electromagnetic fields, to accurately determine the operational range of a radiative near-field on-body radio-frequency identification (RFID) system based on its far field radiation patterns, simulated or measured, under realistic deployment conditions. We illustrate the advocated method by an interrogating 866 MHz standard gain horn (SGH) and a passive eighth-mode substrate integrated waveguide (SIW) textile antenna deployed on an arm. The resulting algorithm is order 10
⁷
times faster than full-wave software, largely outperforms the range calculation via the traditional far field link method and it is capable of very accurately predicting the exchanged power.