A simple reflection/transmission method for study of dielectric and magnetic liquids in the frequency range 0.1-20 GHz

摘要

We propose an appropriate method giving the complex permittivity of a liquid sample from transmission/ reflection measurements obtained from a network analyzer working on a coaxial line between 0.1 and 20 GHz. A specific coaxial cell was made with two etancheity joints in teflon encased at its extremities, Positions and thickness of this joints are taken into account by the calculus. This technique has been tested with the empty cell and then on several dielectric liquids. The results are in excellent agreement with all previous measurements, This method allows also to obtain complex permittivity and permeability of the liquid sample (ferrofluids), but then we have the "length resonance" problem which may be solved with an appropriate algorithm.