This paper demonstrates how motion effect can be exploited to read moving chipless RFID tags at larger distances compared to what has been reached without benifitly taking into account the movement. According to the Doppler effect, due to the time-variant behaviour of moving chipless tags, the tag back-scattered field contains frequency components different from those are transmitted. These motion-induced frequency components can be utilized to efficiently detect the tag at large distances, in a real environment composed of stationary objects. A circuit based analytical model verified by full-wave simulations, is presented to effectively predict the quasi-stationary backscattered field from moving scatterers, with fast computation process. The developed analytic model is applied to rotating dipole scatterers and is used to design chipless tags including an identifier. In term of identification, good agreement is observed between the measurement results and those are predicted by the model. Finally, read range enhancement is proved experimentally by a real environment measurement where the chipless tags are readable at distances up to several meters.

The paper describes how chipless RFID tags in motion can be read at higher distances than what is currently done without taking into account displacement. The movement results in the appearance of a tag backscattered field containing frequencies different from those emitted by the reader according to the Doppler effect. The use of these frequencies not generated by the reader considerably increases the reading distance of the tag, especially in a real environment. This paper is focused on a rotational movement of the tag. The proof of concept is carried out on elementary chipless tags which will be read up to 10 m.

The paper describes how chipless tags attached to non-metal vibrating objects can be utilized to sense the frequency and amplitude of mm-vibration without any calibration process, and to identify the tag from large distances in low microwave frequency band. It is demonstrated that micro-Doppler harmonics induced by vibrating high-resonant scatterers are more detectable than those induced by the vibrating object itself while the scatterers provide great area efficiency. Presented methods for vibration sensing and identification are experimentally validated for sub-millimeter vibrations at distances up to 8 meters.