A Complementary Split-Ring Resonator (CSRR)-Based 2D Displacement Sensor

In this paper, a two-dimensional (2D) displacement sensor based on the diagonal symmetry complementary split-ring resonator (CSRR) structure is proposed. The one-dimensional (1D) displacement sensor is initially developed by etching a ring on the ground plane, and a triangle metal patch is used as the mover. When the mover is attached, a CSRR is formed, thereby inducing a resonant frequency. The displacement of the mover can be retrieved by the variation in the resonant frequency. Then, the structure is extended for designing a 2D displacement sensor. To further reduce the error caused by the lateral displacement, the shape of the sensor is further optimized using the particle swarm algorithm. Finally, the structure of the CSRR displacement sensor is simulated and analyzed, and a physical prototype is made. The measured results are consistent with the theoretical analysis, and its sensitivity is 160 MHz/mm.