Wide-Angle Measurement Based on Arc-Cantilever Beam Interrogated By Open-Ended Hollow Coaxial Cable Resonator

Abstract

In this work, an inclinometer based on arc-cantilever beam for wide-angle measurement is proposed and demonstrated, which is interrogated by an open-ended hollow coaxial cable resonator (OE-HCCR). Two microwave reflectors with high reflectivity are fabricated in a hollow coaxial cable to form an OE-HCCR, which is highly sensitive to the displacement of an external metal plate. An arc-cantilever beam structure is formed as an inclination transducer, which consists of an arc-cantilever, a copper bead placed inside cantilever channel and a metal plate fixed at cantilever center position. The inclination variation leads to bead displacement, which introduces the distance deviation between metal plate and open end, which subsequently modulates OE-HCCR’s resonance frequency. A high inclination sensitivity of -1.2651×10-4 GHz/° within a wide-angle range of -30° ~ 30°, along with a resolution of 0.01146° and a precision of 0.0684°, is experimentally demonstrated, indicating excellent sensing performance of the proposed inclinometer. Additionally, low temperature crosstalk is achieved through temperature compensation. The proposed inclinometer has the potential in monitoring environmental inclinations in various fields, due to the advantages of easy fabrication, high inclination sensitivity and resolution, and enhanced robustness.

Keywords: Inclinometer, Hollow coaxial cable resonator, Microwave reflector, Arc-cantilever beam.