Gas Sensor Platform with Ring Resonator

A ring resonator sensor platform to measure humidity and CO2 gas concentrations is presented which operates at 10GHz. The magnitude and frequency of the resonance are very sensitive to surrounding materials. The sensor can measure humidity and CO2 gas concentrations by placing proper adsorption materials on the resonator. The sensor consists of an adsorption materials, coplanar waveguide (CPW) transmission lines and a ring resonator fabricated on PCB (TLY-5A). A specific adsorption paper is attached to the ring resonator for detecting a specific gas. We use a COCl2 based paper for sensing humidity and a dichlorophenolindophenol (DIP) based paper for sensing carbon-dioxide (CO2) gas. The concentrations are found by analyzing variations of the resonance peak frequency and magnitude.