A reflection type gas sensor using conducting polymer as a variable impedance at microwave frquencies

Yong Joo Lee, Byung Hyun Kim, Hee Jo Lee, Yunseog Hong, Jong Gwan Yook, Hyang Hee Choi, Seung Hwan Lee, Jung Joon Lee

Research output: Contribution to journalConference article

7 Citations (Scopus)

Abstract

In this paper, a gas sensor using a reflection type variable attenuator structure with conducting polymer (CP) is represented. A common gas sensing mechanism is to measure the conductivity or resistance of the CPs when it is exposed to gas. Because conductivity of the CPs varies due to the gas. A novelty in this paper is that the proposed sensor has employed the CPs as impedance-variable transmission lines that cause the impedance mismatching with conventional hybrid coupler. This structure can be thought as a variable attenuator or phase shifter. Experiment is conducted with 100 ppm ethanol gas at a temperature of 28°C and relative humidity of 80% (humidity condition). As a result the amplitude of S11 and the frequency satisfying ∠S21 = -360° is shifted about 2.875 MHz. It is that this reflection type sensor represented.

Original languageEnglish
Article number6985380
Pages (from-to)1819-1822
Number of pages4
JournalProceedings of IEEE Sensors
Volume2014-December
Issue numberDecember
DOIs
Publication statusPublished - 2014 Dec 12
Event13th IEEE SENSORS Conference, SENSORS 2014 - Valencia, Spain
Duration: 2014 Nov 22014 Nov 5

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All Science Journal Classification (ASJC) codes

  • Electrical and Electronic Engineering

Cite this

Lee, Y. J., Kim, B. H., Lee, H. J., Hong, Y., Yook, J. G., Choi, H. H., Lee, S. H., & Lee, J. J. (2014). A reflection type gas sensor using conducting polymer as a variable impedance at microwave frquencies. Proceedings of IEEE Sensors, 2014-December(December), 1819-1822. [6985380]. https://doi.org/10.1109/ICSENS.2014.6985380