Improved permittivity measurement of dielectric substrates by use of the TE111 mode of a split-cylinder cavity

We use the split-cylinder cavity´s TE₁₁₁ resonant mode, in addition to the higher-order TE_0np modes, to extend the frequency range over which one can nondestructively measure the permittivity of dielectric substrates. In addition to the frequency range of the split-cylinder resonator, we also demonstrate that measurements performed with the TE₁₁₁ mode allow us to calculate the frequency of the higher-order TE_0np resonant modes, thus reducing mode-identification errors. We compare relative permittivity measurements of several low-loss dielectric substrates using both the TE₁₁₁ and the higher-order TE_0np modes and employ the Monte Carlo method to calculate the measurement uncertainties.