Complex-Valued Delta RCS Simulation of RFID Tags for Time of Flight Ranging Performance Assessment

For the characterization of a backscatter based radio frequency identification (RFID) tag, delta radar cross section (△RCS) measurements are commonly used. While the magnitude of the △RCS is sufficient for describing basic performance parameters, the evaluation of the accuracy of broadband time-of-flight (ToF) ranging methods requires knowledge of the complex-valued frequency response. This paper introduces an efficient simulation method of the complex-valued △RCS and compares the results to measurements performed in an anechoic chamber. Two tags, a regular ultra high frequency (UHF) tag and a UHF EPC Gen2 compliant dual band tag which allows for ranging in the 2.4 GH _z industrial, scientific, and medical (ISM) band, are investigated. The complex-valued △RCS results are subsequently used to analyze the resulting ranging error of a ToF ranging method.