Mathematical model of non-linear RFID reader — Transponder system

This paper deals with the describing and modeling of inductively coupled radio frequency identification (RFID) system consisting of the transponder and reader basic circuitry where the transponder is considered as a system with non-linear current-voltage characteristic. This non-linear characteristic has significant influence on the signals transferred from the transponder to the reader so the comparison of linear and nonlinear model of the transponder is performed. Moreover the simple measurement method of the non-linear current-voltage characteristic of the RFID transponder chip EM4100 and its approximation by mathematical functions is described.