Method of Monitoring Cracks in Metal Structure Based on Dual-chip RFID Antenna Sensor

The microstrip patch antenna sensor is a novel sensor used for structural health monitoring which can measure metal structure’s crack defects in a wireless manner. However, it is difficult to identify the reflected signal from the signal of antenna sensor. The radio-frequency identification (RFID) antenna sensor, which combines RFID technology and the microstrip patch antenna sensor, can solve the measurement problems that are difficult to the conventional wireless testing technologies. In this study, a dual-chip RFID antenna sensor was designed. The influence of the wireless testing method on the monitoring results of crack defects was investigated by tests, including the wireless tests of resonant frequency and the crack sensitivity tests. The tests results revealed that the antenna sensor had good wireless testing performance with regard to the metal structure’s crack defects. And the maximum of wireless identification distance reached 1.96 m.