On the Effects of the Measured Dielectric Properties at Variable Thickness of Biological Tissue Samples using Open-Ended Coaxial Probe Method

Applications of microwave imaging in the biomedical fields have gained momentum in recent years due to low cost, non-ionizing nature, and non-invasive capabilities. For such imaging applications, the dielectric properties of the specific tissues need to be accurately known where such accuracies are often dependent on the physical attributes such as shapes and sizes of biological samples under test. In this work, the effects of the variable insertion depth of a generic coaxial probe in a biological tissue on the measured permittivity is investigated. Using return loss, the dielectric properties of the material are estimated and compared with the Debye model. The results are in good agreement from 500 MHz to 8 GHz.