A simple experimental set-up for the determination of the complex dielectric permittivity of biological tissues at microwave frequencies

In this paper a simple experimental set-up is presented to determine the complex dielectric permittivity of biological tissues at the industrial frequency of 2.45 GHz. For this purpose, the scattering parameters of biological samples, which are placed in a sample holder inside a waveguide, are measured and compared with those obtained from numerical analysis of the sample using a FE technique with an adaptive mesh. Systematic errors are minimized by a precise calibration of the experimental system. The results obtained are in very good agreement with well-known published data. The simplicity of the experimental set-up makes this technique a very practical tool for detecting and quantifying changes in the complex dielectric permittivity of organs soisoned with heaw metal pollutants.