An Improved Quasi-Optical Cavity for Dielectric Properties Testing of Sheet- and Rod-Shaped Samples

This paper proposed an improved quasi-optical cavity that can be used to measure the dielectric properties of both sheet-shaped and rod-shaped samples. To add a rod-shaped sample testing function to the existing quasi-optical cavity used for sheet-shaped sample testing, two through holes are set on the spherical mirror and the planar mirror of the quasi-optical cavity, and the rod-shaped sample is inserted through the quasi-optical cavity. Meanwhile, based on the cavity perturbation method (CPM), a test algorithm for the complex permittivity measurement of rod-shaped samples is proposed. The proposed method effectively extends the measurable sample types of the existing quasi-optical cavity dielectric properties test system, which is of great significance for the study of millimeter-wave dielectric properties of materials.