Noncontact microwave material characterization

In this paper, a nondestructive method for the non-contact characterization of non-planar dielectric objects is presented. Traditionally, this kind of measurements is achieved by using spot-focused antennas associated to a vector automatic network analyzer. In this study, we propose a free space measurement system, fitted out with a classical horn antenna, which demonstrates its usefulness in many practical cases. The permittivity is computed from the reflection coefficient of metal-backed samples of different shapes at 2.45 GHz.