Broadband microwave gas sensor: A coaxial design

The method of gas detection by a broadband microwave gas sensor is presented in this article. The principle of this method is to use a sensitive material as substrate of a transmission coaxial line. The sensor represents an open line with an extreme surface in contact with gas. The interaction with the gas and the surface induces a dielectric variation of the substrate. From experimental results, the interaction between the sensitive material and each tested gas present a specific frequency spectrum of the reflection coefficient at the input of the line. The proposed method has the advantage of a compact size, wide bandwidth, simple structure, and capable with all sensitive materials. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52: 1739–1741, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.25359