Compass-shaped RFID Sensor Tag for Metal Crack Detection

This paper presents the simulation study of RFID sensor tag for metal crack detection. The sensor tag comprised of a compass-shaped patch antenna as a crack sensor and two L-shaped resonators as identification encoder. The sensor tag is placed on metal sheet to be monitored. The compass-shaped patch antenna resonates at frequency 4.48 GHz and L-shaped resonators provides resonant frequencies of 3.37 GHz and 3.60 GHz in radar cross section (RCS)-frequency characteristics. The orientation and width of crack are monitored by shift in resonant frequency of compass-shaped patch antenna. However, identification code of tag in terms of resonant frequencies remains unchanged in the presence of crack. The simulation results verify that the proposed sensor tag can sense the crack on metallic object and identify the object simultaneously.