This paper presents a coaxial resonator for dielectric measurements of low and medium loss liquids at multiple resonance frequencies up to 8 GHz with the fundamental transverse electromagnetic (TEM) resonant mode at 2 GHz. The measurement is by filling the entire resonator cavity with the material under test and the permittivity of the material is readily extracted using simple equations. This technique provides an easy and accurate extraction method of dielectric properties without any analytical approximation and dedicated software algorithm as used in broadband open coaxial probes or the complex perturbation formula in resonator‐based methods. This significantly reduces the risk of systematic errors from the model approximation. The measured quality factor of the resonator is 2650 to 3500 depending on the resonant mode. This allows for the measurement of samples with loss tangents up to 0.05 (Acetone taken as a reference). The device was made by 3D printing and verified by measurements of several common solvents at all four resonance frequencies. The results obtained agree well with values reported in literature. Further measurements of crude oil samples were carried out and results confirmed with values obtained using other techniques.

中文翻译：

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3D打印同轴微波谐振器传感器，用于液体的介电测量

本文提出了一种同轴谐振器，用于在高达8 GHz的多个谐振频率下对低损耗和中损耗液体进行介电测量，基本横向电磁（TEM）谐振模式为2 GHz。通过在整个谐振腔中填充被测材料来进行测量，并使用简单的公式轻松提取材料的介电常数。该技术提供了一种简单而准确的介电特性提取方法，而无需任何分析近似和专用软件算法，如宽带开放式同轴探头中使用的方法或基于谐振器的方法中的复杂扰动公式。这大大降低了因模型逼近而导致系统误差的风险。根据谐振模式，测得的谐振器品质因数为2650至3500。这样可以测量损耗角正切值高达0.05的样品（丙酮作为参考）。该设备通过3D打印制成，并通过在所有四个共振频率下对几种常见溶剂的测量进行验证。获得的结果与文献报道的值非常吻合。进行了原油样品的进一步测量，并用其他技术获得的值证实了结果。