New Measurement Method of Broadband Permittivity and Permeability of Non-Solid Materials in Small Quantity

We propose a new measurement method for the simultaneous evaluation of permittivity and permeability of small amount of materials in powder, liquid, or gel form. A plastic toroidal case was used to encapsulate non-solid material under test (MUT), and the whole case was subjected to coaxial line analysis. The volume of MUT required for the case was established as approximately 70 μL, and we removed the plastic parts using high-frequency circuit theory. As a result, constant and nearly ideal relative permittivity and permeability of air were confirmed. Measuring permeability at microwave band of magnetic powder above 45 vol% became possible using the proposed method.