A 3D Printed Sensor Based on Microwave Transversal Signal Interference Principle with Simultaneous Angular Displacement and Inclination Detection

This paper presents a novel 3D-printed sensor that simultaneously measures angular displacement and spatial inclination. The sensor utilizes suspended microstrip technology and employs PLA (Polylactic Acid) as the substrate material, operating at a frequency of 1.3GHz. Regarding angular displacement sensing, the sensor exhibits a dynamic range from 0° to 180°, with a sensitivity of 4.64MHz/°. The sensing mechanism utilizes two-notch frequencies or transmission zeros within the frequency spectrum, generated through microwave dual-path transverse signal interference (TSI). The value of these frequencies varies according to the displacement being measured. Additionally, the study investigates the impact of hollowing the substrate, injecting water, and controlling different water levels on the dielectric properties. The results demonstrate the effectiveness of the proposed method for angular displacement sensing and its potential for inclination sensing simultaneously.