Microbead-assisted high resolution microwave planar ring resonator for organic-vapor sensing

• Author(s) / Creator(s)

  • Zarifi, Mohammad H.
  • Fayaz, Mohammadreza
  • Goldthorp, Jordan
  • Abdolrazzaghi, Mohammad
  • Hashisho, Zaher
  • Daneshmand, Mojgan

• A microbead-assisted planar microwave resonator for organic vaporsensing applications is presented. The core of this sensor is a planarmicrostrip split-ring resonator, integrated with an active feedback loop to enhance the initial quality factor from 200 to ∼1 M at an operational resonance frequency of 1.42 GHz. Two different types of microbeads, beaded activated carbon (BAC) and polymer based (V503) beads, are investigated in non-contact mode for use as gas adsorbents in the gas sensing device. 2-Butoxyethanol (BE) is used in various concentrations as the target gas, and the transmitted power (S21) of the two port resonatoris measured. The two main microwave parameters of resonance frequency and quality factor are extracted from S21 since these parameters are less susceptible to environmental and instrumental noisethan the amplitude. Measured results demonstrate a minimum resonance frequency shift of 10 kHz for a 35 ppm concentration of BE exposure to carbon beads and 160 kHz for the polymer based adsorbent at the same concentration. The quality factor of the resonator also changed for different concentrations, but a distinguishable variation is observed for the BAC adsorbents. The high quality factor of the sensor provides the opportunity of real time monitoring of the adsorbent behaviors in remote sensing mode with very high resolution.

• Date created

  2015-01-01

• Subjects / Keywords

  • Gas Sensors
  • Carbon
  • Adsorption
  • Microwaves
  • Permittivity

• Type of Item

  Article (Published)

• DOI

  https://doi.org/10.7939/r3-rwk0-q787

• License

  © 2015 AIP Publishing LLC. This article may be downloaded for personal use only. Any other use requires prior permission of the author and AIP Publishing. This article appeared in Zarifi, Mohammad H., Fayaz, Mohammadreza, Goldthorp, Jordan, Abdolrazzaghi, Mohammad, Hashisho, Zaher, & Daneshmand, Mojgan. (2015). Microbead-assisted high resolution microwave planar ring resonator for organic-vapor sensing. Applied Physics Letters, 106(6), 062903 and may be found at http://doi.org/10.1063/1.4907944