Split-cylinder resonator operating in TE01p modes for determining the complex permittivity of dielectric sheets in...

This paper provides a highly comprehensible and effective method for calculating fringe field effects in TE01p mode split-cylinder resonators, enabling high-accuracy measurements across wideband and multiple frequency points. In particular, the dielectric-filled flange is treated as a shape perturbation extending outward from an ideal closed cavity to calculate the frequency offset, which in turn corrects the measured frequency for permittivity extraction. Compared with the commonly used and most efficient mode matching technique, the proposed method achieves comparable high accuracy while effectively overcoming its inherent challenges, such as the high sensitivity of iterations to initial guesses and the risk of non-convergence or erroneous mode identification caused by multiple roots in higher-order modes. In addition, we fabricated a SCR that can operate from 17 to 40 GHz and measured PTFE, fused silica, RO3003, and sapphire samples, respectively, which are commonly used as reference samples. The test results show very good agreement with literature references.