A Centimeter-Range Displacement Sensor Based on a Hollow Coaxial Cable Fabry-Perot Resonator


This paper reports a novel hollow coaxial cable Fabry-Perot resonator for centimeter-range displacement measurements. The sensor is fabricated on a novel homemade hollow coaxial cable in which the traditional insulating layer is replaced by air. Two highly reflective reflectors are engineered on this hollow coaxial cable to form a Fabry-Perot resonator in radio frequency domain. The first reflector is fixed, while the second reflector is movable and is permanently connected to a tubular measurement handgrip. The device physics was described. When a displacement is applied to the measurement handgrip, the cavity length of the resonator will change. The change in the cavity length can be determined by tracking the shift in the resonant frequency. The displacement responses and measurement stability of the novel sensor were tested. The experimental results show that the novel hollow coaxial cable-based displacement sensor has a dynamic measurement range of 14 mm with a resolution of 10 µm. The temperature-displacement cross-sensitivity was also investigated. The dynamic range of the Fabry-Perot resonator-based displacement sensor can be easily extended to meter range by employing a meter-long hollow coaxial cable. The reported novel sensor is cost-effective, robust, and easy-to-manufacture, so in situ the sensor can be easily commercialized and has great potential for applications in the construction industry, petroleum industry, and other industries.


Electrical and Computer Engineering

Research Center/Lab(s)

Intelligent Systems Center


University of Missouri Research Board


This work was supported by the University of Missouri Research Board.

Keywords and Phrases

Cavity resonators; Coaxial cables; Construction industry; Cost effectiveness; Electric conductors; Fabry-Perot interferometers; Frequency domain analysis; Natural frequencies; Petroleum industry; Reflection; Sensors; Steel; Displacement response; Displacement sensor; Dynamic measurement; Fabry-Perot resonators; Harsh environment; Insulating layers; Radio frequency domains; Wide-range displacement, Displacement measurement; Hollow coaxial cable

International Standard Serial Number (ISSN)

1530-437X; 1558-1748

Document Type

Article - Journal

Document Version


File Type





© 2018 Institute of Electrical and Electronics Engineers (IEEE), All rights reserved.

Publication Date

01 Jun 2018