Motion-Modulated Chipless RFID

Abstract

This paper addresses the new type of backscatter communication based on motion-modulated chipless Radio Frequency IDentification (RFID) tags. To clearly explain the concept, the different methods of backscatter communication are classified from a system point of view based on the two fundamental properties of linearity and variation in time. The principle of classical chipless RFID technology, as a non-modulated backscatter method, and the motion-modulated chipless RFID are described with general mathematical demonstrations, while the performance of the two approaches is compared in terms of read range. Motion-modulated chipless RFID is presented as an effective backscatter communication method for identification and sensing of moving objects at large distances. Three different types of motion-induced modulation as phase (Doppler) modulation, polarization modulation, and directional modulation are addressed based on three specially designed moving resonant scatterers. The modulation process in each case is theoretically described, and the performance of the motion-modulated tag is experimentally verified in terms of identification capability and large read range.