Dielectric characterization of materials using a modified microstrip ring resonator technique

The goal of this study is to present a simple model based on the ring-resonator technique to measure nondestructively the permittivity and loss tangent of dielectric materials. The proposed measurement model utilizes a modified ring-resonator technique in one-layer and two-layer microstrip configurations. This method eliminates the requirement to metalize the samples and enables characterization of permittivity and dielectric loss from 2 to 40 GHz. The effects of conductor and radiation losses that may introduce significant errors in the calculation of the loss tangent, especially at very high frequencies, are minimized. The measurement precision is evaluated by comparing the results with those obtained by using two well-known standard techniques. Uncertainties associated with the proposed model are addressed.