Reflection spectroscopy on solutions of biological materials in millimeter wave frequency

We attempted to analyze a solution of biological matter of sugars, amino-acids, and electrolytes using a millimeter-wave reflection spectroscopy. The sensitivity for the concentration of solutes was improved markedly, when an adequate dielectric layer was inserted at the interface of incident side of the solution as impedance matched layer. The sensitivity was covered fully in the range of adequate blood sugar level of human as 0.07-0.16 g/100ml H₂O in the case of glucose solution.