Multipath Interference Analysis for Low-Power RFID-Sensor Under Metal Medium Environment

Abstract

Mechanism analysis of the radio frequency identification (RFID)-sensor communication interference can effectively improve the information collection quality of the perception layer. In our study, multipath interference analysis of low-power RFID-sensor under a metal medium environment was considered. First, the dual-antenna RFID-sensor architecture was developed based on a low-power strategy. The multipath loss model and interference theory under a metal medium environment were discussed. Second, by full consideration of electromagnetic interference energy loss factors, the time–frequency domain characteristics of electromagnetic signals, such as direct radiation, refraction, diffraction, scattering, absorption, and polarization were analyzed. Third, the normalized electric field strength between the low-power RFID-sensor with different distances was obtained through simulation/experiment scenarios. The distance between the low-power RFID-sensor and transmitting antennas is represented by <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${r}$ </tex-math></inline-formula> . When <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${r}$ </tex-math></inline-formula> is from 1 to 5 m, the minimum working distance between the RFID-sensor antenna and the metal medium surface changes from 6.9 to 7.0 mm at a frequency of 915 MHz. This article was conducive to expanding the functions of the perception layer system of the Internet of Things (IoT) and enhancing the application potential of existing RFID and sensor networks.