A Novel Q-Choked Sapphire Sandwiched Resonator for Wideband Measurements of Flat Dielectric Samples

A novel Q-choked sapphire sandwiched resonator (Q-SSR) is designed, fabricated, and validated for fast and nondestructive testing of materials between upper microwave and lower millimeter-wave (mm-Wave) frequencies. It combines the advantages of the recently proposed Q-choked split cylinder resonator (SCR), where the choke ensures a spectrum of pure TE_0np modes, with the dielectric focusing properties of split-post dielectric resonators (SPDRs), which increase sensitivity and decrease losses in cavity walls. A Q-SSR prototype operating at seven modes in the 12–30 GHz band is applied to reference samples defined in industrial benchmarking initiatives. It produces complex permittivity results in excellent agreement with SCR, SPDR, and Fabry–Perot open resonator (FPOR) techniques, at a competitive effort.