The microwave waveguide and resonator methods are compared as applied to the experimental determination of the dielectric properties of high loss liquids. A differential microwave waveguide cavity for measuring high loss liquids complex permittivity in a small volume has been designed and studied. This cavity consists of two circular waveguide cells with central rods made of quartz and surrounded by high loss liquid tested. The cells have different lengths to eliminate complex propagation coefficient measurement errors due to the diffraction effect on the ends of the layered waveguide cells. We have measured the wave amplitude and phase coefficients for the waveguide cavity to estimate physical properties of a high loss liquid under test. The resonant frequencies and the Q-factor of a semi-disk dielectric resonator with high loss liquid filling a capillary have been measured. We have selected water-ethanol solutions as a high loss liquid under test for both techniques. We have determined the measurement sensitivity for these two techniques. The measuring results are discussed. Both the waveguide and resonator methods provide comparable sensitivity and can be successfully used for the complex permittivity characterization of high loss liquids in small volumes.

中文翻译：

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高损耗液体介电特性：微波波导和谐振器测量技术的比较

将微波波导和谐振器方法应用于高损耗液体介电特性的实验测定中进行了比较。设计并研究了一种用于测量小体积内高损耗液体复介电常数的微分微波波导腔。该腔由两个圆形波导单元组成，中心杆由石英制成，并被测试的高损耗液体包围。这些单元具有不同的长度，以消除由于分层波导单元末端的衍射效应而导致的复杂传播系数测量误差。我们测量了波导腔的波幅和相位系数，以估计被测高损耗液体的物理特性。谐振频率和问测量了填充毛细管的高损耗液体的半圆盘介质谐振器的系数。我们选择了水-乙醇溶液作为两种技术测试中的高损失液体。我们已经确定了这两种技术的测量灵敏度。讨论了测量结果。波导和谐振器方法都提供了相当的灵敏度，并且可以成功地用于小体积高损耗液体的复介电常数表征。