▎ 摘　　要

NOVELTY - The sensor tag has a RFID tag antenna including an antenna radiator (2) and a metal feeding ring. The antenna radiator is attached to the flexible substrate (1). The metal feeding ring (4) is arranged on one side of the antenna radiator through the feeding ring substrate (3). The tag chip (5) is located on the feed ring substrate and connected to the metal feed ring. The RFID sensing tag is used to monitor the strain generated by an object or the relative motion between two objects. The flexible substrate is installed on the surface of the object to be measured when used to monitor the strain generated by the object. The feed ring substrate is installed on the flexible substrate. The flexible base and the feed ring substrate are respectively located on two objects to be measured when used to monitor the relative motion between two objects. USE - Coupled feed structure based-flexible radio frequency identification (RFID) sensor tag used in distributed monitoring system to monitor strain generated by object or relative motion between two objects. ADVANTAGE - The RFID sensor tag can monitor the strain or relative movement in the X and Y axis directions without changing the arrangement. The metal feeding ring and the antenna radiator adopt a separate design, and the electromagnetic induction between the metal feeding ring and the antenna radiator is used for feeding, which can avoid the performance degradation of the antenna. The RFID sensor tag overcomes the defect that the existing RFID sensors can only monitor the strain in a single direction without changing the layout. The RFID sensor tag can be used to monitor the relative motion between two objects, thus realizing non-contact measurement. The ink prepared from graphene is printed on a flexible substrate to form a film by virtue of the self-supporting property of graphene, and the graphene film is made denser and the adhesion of the graphene film is improved by pressing. The RFID sensor tag avoids the high-temperature annealing process and the volatilization of irritating gases, further reducing manufacturing costs. The graphene and carbon nanotubes or carbon black used as conductive fillers improves the conductive network of the graphene film, thus improving conductivity. The RFID sensor tag has good flexibility and stability, can realize complete wireless passive real-time monitoring, and can be used on different curved surfaces. DESCRIPTION OF DRAWING(S) - The drawing shows a schematic diagram of a coupled feed structure based-RFID sensor tag. 1Flexible substrate 2Antenna radiator 3Feeding ring substrate 4Metal feeding ring 5Tag chip