Microwave Device Inspired by Fiber-Optic Extrinsic Fabry-Perot Interferometer: A Novel Ultra-Sensitive Sensing Platform


The fiber-optic extrinsic Fabry-Perot interferometer (EFPI) is one of the simplest sensing configurations and is widely used in various applications. Inspired by the EFPI, we report a novel and universal ultra-sensitive microwave sensing platform based on an open-ended hollow coaxial cable resonator. Two highly-reflective microwave reflectors were fabricated in a coaxial cable to form a microwave Fabry-Perot etalon. Although the operating wavelength of the proposed device is increased by five orders of magnitude compared to the fiber-optic EFPI (e.g., from 1500 nm to 150 mm), the resolution regarding the 'pseudo cavity length' of the proposed device is as high as 0.6 nanometer, which is comparable to that of the EFPI. The resolution can be further increased by high-precision machining of the device. Due to its low cost, high sensitivity, all-metal structure, robustness, and ease of signal demodulation, it is envisioned that the proposed device will revolutionize the sensing field and enable many important sensing applications that take place in harsh environments.


Electrical and Computer Engineering

Research Center/Lab(s)

Intelligent Systems Center


Army Research Laboratory, Grant W911NF-14-2-0034

Keywords and Phrases

Displacement; Extrinsic Fabry-Perot Interferometer; Fiber-Optic Sensor; Microwave Device; Open-Ended Coaxial Cable Resonator

International Standard Serial Number (ISSN)

0733-8724; 1558-2213

Document Type

Article - Journal

Document Version


File Type





© 2020 Institute of Electrical and Electronics Engineers (IEEE), All rights reserved.

Publication Date

20 Aug 2020