Accurate and efficient measurements for complex permittivity of 3D printer filaments using a 50GHz band TM010 mode cavity resonator

An additive manufacturing technique with an FDM type 3D printer is an attractive and novel fabrication technology to develop microwave and millimeter wave components. Nevertheless there are few reports for complex permittivity of 3D printer filament materials. We have been presented a thin dielectric rod measurement method using a 50GHz band TM 010 mode cavity resonator and an improved perturbation formula corrected with FEM simulations. However, this method takes long time due to a lot of FEM calculations. In this paper, an accurate and efficient complex permittivity measurement method for a thin dielectric rod is proposed using the 50GHz band TM 010 mode cavity resonator based on a rigorous analysis by a mode matching method. In addition, the measured results of complex permittivity for three kinds of 3D printer filaments are shown at 45GHz band.