Transmission Phase-Shift Method for Complex Permittivity Determination of Biological Sample Performed Using X-Band Rectangular Waveguide

Determination of material properties is one of essential stages to more understanding the characteristics of biological sample especially in biomedical research. In this paper, a method of transmission phase-shift is proposed to determine complex permittivity of biological sample which is performed using a WR90 type X-band rectangular waveguide. Some samples of chicken meat, liver, and skin are applied as biological materials for the experimentation. The irregular shape of biological sample is examined by placing it into a thin container to obtain a flat surface and putting the container in inside of the rectangular waveguide. The complex relative permittivity of each sample is extracted from measured S-parameters and then determined using the method. The results show that the method could successfully determine the complex permittivity of biological sample. In addition, the water content in the material has become a critical issue to be considered in the examination especially for the biological sample with high permittivity.