A Novel Multidirectional Strain Sensor Realized by a 3D Microstrip-Line Fed Near-Circular Patch Antenna

摘要

In this paper, we propose a newly developed impedance method to gauge the variations of multidirectional strain using a near-circular-patch based sensor. A novel three-dimensional (3D) feeding mechanism realized by a 90-deg bended microstrip line is devised for allowing strain detection along any direction in the azimuth plane of a metallic surface. The simulated results, verified by experimental results, demonstrate that there is a linear relationship between normalized impedance and multi-directional strain with high sensitivities of about 100 ppm/mu epsilon. The relationship between sensitivity and sensor orientation is derived as a cosine function, which is a useful feature for estimating principal strain direction.