Influence of the Design in Microwave-based Gas Sensors: Ammonia Detection with Titania Nanoparticles

This work presents new microwave-based sensing measurements for the detection of NH3 using metal-oxide sensitive layers, namely titanium dioxide nanoparticles (P25 Degussa). Several designs have been tested to assess the influence of the design on the microwave gas sensing response. The results for microstrip interdigital capacitor, rectangular spiral antenna and spiral resonator are presented over a wide range of frequencies (2-8GHz). All designs were firstly optimized by numerical simulation, then experimentally tested in presence of ammonia (from 100 to 500ppm in an argon flow).