Obstacle-based self-calibration techniques for the determination of the permittivity of liquids

[摘要] In this contribution, different obstacle-based self-calibrationtechniques for the measurement of the dielectric properties ofliquids are investigated at microwave frequencies. The liquidunder test is contained inside a waveguide, which is connected tothe ports of a vector network analyzer. The permittivity of theliquid is characterized on the basis of the measured scatteringparameters.

In order to extract the material parameters precisely and toeliminate systematic errors of the setup, calibration measurementshave to be performed. For this purpose, different self-calibrationmethods based on the displacement of an obstacle are considered.The presented methods differ in that way, that either transmissionand reflection measurements or purely reflection measurements areperformed. All these methods have in common that the materialparameters are already calculable within a so-calledself-calibration procedure. Thus, a full two-port calibration ofthe whole setup is not necessary. Furthermore, the methods can berealized effectively in a practical setup having the advantagethat a rearrangement of the setup is not needed for the materialparameter measurements and that the liquid under investigation canpass continuously through the measurement cell. This might be ofinterest for the application in an industrial process, enablingthe continuous flow of the material while the parametercharacterization can take place at the same time.

[学科分类] 电子、光学、磁材料