A multiband 2-port vector network analyzer based on Six-Port junctions for biomedical measurement applications between 6 GHz and 33 GHz

Concentration measurements of dissolved substances in fluids are of great interest for biomedical as well as industrial applications. In this work a multiband vector network analyzer is presented that is capable of determining phase variations due to changes in the concentration. A topology comprising two Six-Port networks optimized for the frequencies 6.6 GHz, 19.7 GHz and 32.4 GHz has been implemented. Measurement results show a characteristic change of the phase when increasing the glucose concentration in binary aqueous solutions.