Dielectric characterization of printed wiring board materials: a comparison of ring and T-resonator based measurement methods

Dielectric characterization of printed wiring board materials is important for ensuring designed performance of printed wiring board products. Ring and T-resonator type planar transmission line resonators are widely used for dielectric characterization of printed wiring board materials. The measurement methods that are based on the ring and T-resonators are both broadband and the direction of the electric field is normal to a face of a measurement sample. A comparison between the ring and T-resonator based methods is presented in this article. The comparison is based on an experimental research that is carried out with one FR-4 type printed wiring board material at wide frequency range. The results of the comparison prove that with the ring and T-resonator based measurement methods can be achieved similar results in dielectric characterization of FR-4 type printed wiring board materials.