Development of gas sensors on microstrip disk resonators

Here it is reported about the development of microwave disk resonators and their employment as transducers in gas sensing devices. The sensors were developed by designing, modeling and realizing microstrip resonators on several microwave substrates, and by depositing sensing films on the disk. The transduction mechanism can be explained through the change in the permittivity value, in a low thickness of the sensing film, due to the interaction with the gas target. Furthermore, due to the microwave penetration on the sensing material, the response depends on volume effect, not only on surface one. These devices own intrinsic stability due to the fact that the resonance frequency value is related to the physical dimensions.