The measurements of the dielectric properties of materials are subject of numerous studies due to their implications in various application fields. The ability to monitor non-destructively and in real-time the response of materials to electromagnetic fields at microwave and terahertz frequencies provides useful information about various physical and chemical parameters of the material under test. For a specific orientation of the electric field and a fixed working frequency, the electromagnetic properties of a substance can be related to physical parameters such as temperature, concentration, pressure, humidity, mechanical stress, molecular structure, and so on. Therefore, such sensors are of interest in many application contexts, including:

- Food industry and agriculture: estimation of heating rates when the materials are exposed to high intensity fields, determination of moisture content, food storage, verification of product quality, etc.;

- Medical and pharmaceutical industry: tissue characterization, testing and production of drugs, characterization of solvents, chemical reactions, etc.;

- Electronics industry: characterization of substrates, printed circuit boards, etc.;

- Aerospace/defense industry: radar absorbent materials, radomes, etc.

In this framework, the activities carried out by researchers of IREA are devoted to the design and characterization of microwave sensors (e.g. sensors for the characterization of liquid solutions and bioradar sensors), and to investigations at THz frequencies in order to carry out a quantitative characterization of materials by exploiting their unique spectral response in this band.