Free-Space Method for Measurement of Dielectric Properties at Microwave Frequencies

Abstract

Industries need a better understanding of the materials to shorten design time. The accurate measurement can provide valuable information to properly use the material for solid design or monitoring processes. Every material has a unique electrical characteristic that depends on its dielectric properties. This paper presents the free-space measurements to determine the dielectric properties of the material under test. The main objective was to measure the dielectric properties of different materials at microwave frequencies. The frequency range in this measurement setup is 8–12 GHz (X band). The measurement setup includes a Vector Network Analyzer, horn antennas, calibration kit, and simulation software to determine the dielectric properties of the material under test. In this work, the transmission coefficient (S-parameter) was measured to obtain the amplitude and phase of the material under test. This study developed an extraction procedure by finite element simulation. The measurement setup was remodeled in the HFSS simulation according to all parameters used in the measurement setup settings. Simulations are used to extract the dielectric properties of the material under test from measurement results. The extraction result was tabulated and compared with the other references.