Measurement of Multiband Complex Permittivity by Perturbation Insertion Method

In this paper, a single rectangular resonant cavity is proposed to achieve complex permittivity measurements in multiple working modes in the frequency band range of 1.6–10 GHz by perturbation-insertion method. The center of the cavity is used as the location for insertion of the material to be measured, TE101, TE103, TE105 and TE109 are selected as the working modes. The influence of the depolarization field on the material is considered, and the equation for the effective depolarization factor is obtained by fitting the simulation. Based on simulations and measurements, the complex permittivity values calculated by the proposed work are very close to the reference values.