Strain Measurement Technique Based on Rectangular Patch Antenna

To study the strain measurement technique based on the rectangular patch antenna, according to the transmission line model, the interaction mechanism between rectangular patch antenna and strain was analyzed. The effect of strain on the dimensional size of the radiating area of the patch antenna can shift the central frequency of the antenna. The linear relationship between frequency shift and the strain was also obtained. Three types of rectangular patch antennas with different center frequencies were designed. Simulation and experiments were carried out to extract the variation of the central frequency versus structural strain, using high frequency structure simulator (HFSS) and tensile strain testing system on different strain states. According to the simulation and experimental results, the relationship between the shift of the center frequency of the patch antenna and the strain is obviously linear. The higher the center frequency of the patch antenna is, the greater the strain sensitivity is obtained. This shows that the rectangular patch antenna, as a strain sensor, can meet the requirements of structural strain measurement, which lays a foundation for the wireless structural health monitoring.