Design of Nanostructured Graphene Based RF Complementary Split Ring Resonator Gas Sensor for Detection of Nitrogen Dioxide

The complementary split ring resonator (CSRR) incorporated with the nanostructured graphene is proposed to design an efficient RF gas sensor. The nanostructured graphene is synthesized using the nitrogen rich cow urine, which can also be termed as the nitrogen doped graphene (NGn). The CSRR is etched on back side of the microstrip line designed on a FR4 substrate, and is excited by the electric field from top of the line. In this study, the nitrogen dioxide (NO
₂
) gas is detected by tracking the shift in the resonant frequency of the measured transmission coefficient (S21) of the designed sensor when it is exposed to the gaseous environment. The gas sensing capability of designed NGn-CSRR sensor is tested at room temperature using 50-200 ppm of NO
₂
. A shift in the resonant frequency of 51 MHz is observed even for as low as 50 ppm of NO
₂
molecules interacting with NGn surface of the designed sensor. The detection of very low traces of NO
₂
by the proposed NGn-CSRR RF sensor shows its application for NO
₂
sensing in harsh environment.