Microwave-based gas sensor with phthalocyanine film at room temperature

Microwave gas sensing with a microstrip interDigital capacitor: Detection of NH3 with TiO2 nanoparticles

“…In a toluene detection study realized with a PcCo-covered coplanar waveguide, Rossignol et al have reported interesting results where each concentration could not simply be described by a point on the real vs imaginary plot [14]. Each concentration outlined an arc of a circle, whose distance from the origin point ([0;0] for 0 ppm) was strongly correlated with the toluene concentration present in the cell.…”

“…Ammonia, toluene Dynamic S11 real and imaginary parts variation [14] Coplanar waveguide Zeolite Toluene Dynamic S11 real and imaginary parts variation [7] Hybrid coupler…”

VOCs Detection by Microwave Transduction Using Zeolites as Sensitive Material

“…The response of the microwave sensor leads to the obtention of a reflection coefficient at each frequency. This one is a complex number representing the ratio between the incident electromagnetic wave at the input of the circuit and the reflected wave [1,6].…”

“…This transduction brings several advantages: the measurements are performed at room temperature [6] (without energy supply to the sensitive material) and allow the obtention of a couple of values (imaginary and real part of the response) for each frequency which gives a specific signature of the gas-material interaction on the whole scanned frequency spectrum.…”

Planar Microstrip Ring Resonator Structure for Gas Sensing and Humidity Sensing Purposes

“…They have been attracting research interest in recent years [9][10][11][12]. They are even applied in automotive exhausts to monitor directly the status of zeolite-based SCR catalysts [13,14].…”