Characterization method of film-shaped materials. Pressure effect measurement on the electromagnetic properties into an absorbent material of compressed powder

A broadband electromagnetic characterization method of film-shaped materials is developed. Complex permittivity is computed from S-parameter measurements of microstrip lines propagating the quasi-TEM mode and used as cells. The measurement bench employs an on-microstrip test fixture. Measurements (0.05-40 GHz) for alumina show good agreement between measured and predicted data. This method is used to show the pressure effect on the electromagnetic properties into an absorbent disk due to its fabrication process.