A non-invasive approach for moisture measurements through patch antennas

Different approaches and techniques are commonly available for the continuous monitoring of moisture levels and dielectric properties of materials; typically, related applications, are largely used in soil science area. Nevertheless, the state of the art is actually rather lacking in specific sensing methods that combine the low cost and the non-invasive approach of the involved instrumentation. To fill this gap, in this paper the authors study the feasibility of the adoption of the time-domain reflectometry analysis for such purposes, using a patch antenna as sensing element. This way, the extrapolation of the scattering parameters is suitably correlated to the water content levels of the materials under test. Furthermore, the adopted methodology is assessed through full-wave simulations, thus corroborating the experimental measurements. ©2008 IEEE.