Microwave Gas Sensor based on Graphene-loaded Substrate Integrated Waveguide Cavity Resonator

Mohammad Ashraf Ali, Mark Ming Cheng Cheng, Jimmy Ching Ming Chen, Chung Tse Michael Wu

Research output: Chapter in Book/Report/Conference proceedingConference contribution

23 Scopus citations


In this paper, novel microwave gas sensors based on graphene-loaded substrate integrated waveguide (SIW) cavity resonators are presented. Two SIW-based cavity resonators, a ring-slot resonator and a complementary split ring resonator (CSRR), are fabricated and coated with chemical vapor deposited (CVD)-grown graphene. The fabricated graphene contains a layer of polymethyl methacrylate (PMMA) on its top. The graphene sheets exhibit high sensitivity to various kinds of polar and non-polar gases. When polar gas contacts the graphene sheet, it will donate or receive electrons, thereby changing its conductance. The SIW cavities thus perform a resonant frequency shift from the perturbation of electron exchange. In the experiment, a frequency shift of 59 MHz and 157 MHz for the SIW ring-slot resonator and CSRR, respectively, can be observed after pure ammonia gas is injected into a closed chamber filled with air at standard atmospheric pressure and temperature. This work demonstrates a very simple and efficient gas sensing scheme in the microwave regime. The proposed devices are promising to be further integrated with RF front-ends, providing a low cost and high sensitive gas sensing and environmental monitoring solution.

Original languageEnglish (US)
Title of host publication2016 IEEE MTT-S International Microwave Symposium, IMS 2016
PublisherInstitute of Electrical and Electronics Engineers Inc.
ISBN (Electronic)9781509006984
StatePublished - Aug 9 2016
Externally publishedYes
Event2016 IEEE MTT-S International Microwave Symposium, IMS 2016 - San Francisco, United States
Duration: May 22 2016May 27 2016

Publication series

NameIEEE MTT-S International Microwave Symposium Digest
ISSN (Print)0149-645X


Other2016 IEEE MTT-S International Microwave Symposium, IMS 2016
Country/TerritoryUnited States
CitySan Francisco

All Science Journal Classification (ASJC) codes

  • Radiation
  • Condensed Matter Physics
  • Electrical and Electronic Engineering


  • Ammonia gas sensor
  • chemical vapor deposition
  • complementary ring resonators
  • gas sensor
  • graphene
  • substrate integrated waveguide (SIW)


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