Un metodo per il rilevamento della porosità di materiali dielettrici mediante misure in campo vicino con antenne a patch

A non-destructive, non-invasive technique for porosity detection in samples of dielectric materials is described. The sample porosity is derived from the variation of dielectric permittivity of the sample with respect to dielectric permittivity of the intrinsic material; the permittivity is assessed using a microwave sensor, whose resonance frequency depends on the dielectric constant of the material under test. Different degrees of porosity have been artificially induced into samples of polymeric materials; measurements obtained by the described technique are in good accordance with conventional measurements based on physical characteristics (mass and volume) of the samples