Obliquely cut open ended coaxial probe for obtaining complex permittivity of lossy materials

In microwave frequencies, the usual technique to measure the complex permittivity of high lossy material as human tissue is to use the open ended coaxial probe. In this paper, to carry reliable contact between the open end and the measuring sample, obliquely cut open ended coaxial probe has been developed. The result of measurement for sample is compared with those obtained from Debye equation. From the results, it is found that by the obliquely cut open coaxial probe, the complex permittivity of ethanol with the purity of 99.5% can be measured. In addition, the electric field distribution is simulated to confirm the area of measurement. By this measuring system, it can be measured for deep point in the material and biological body.