Measuring Complex Permittivity of Soils by Waveguide Transmission/Reflection Method

The transmission line method for measuring the complex permittivity of material via the S-parameter has been widely researched. In this paper, the rationale of the transmission line method is derived clearly, especially for the optimized solutions for the multivalued issue and the thickness resonance are presented. The revised algorithm is employed to evaluated the complex permittivities of soil in terms of various of water content at frequencies between 500MHz and 10GHz. The experiment shows that there not exist the multivalued issue and the thickness resonance in the retrieving results, it is indicated that the complex permittivities of soil can be obtained by the advanced transmission line method.