The coaxial probe technique is used to acquire the dielectric properties of biological tissues in the microwave frequency range. To dielectrically characterize heterogeneous samples, the sensing radius of the probe must be known. Thus, in this article, for the first time, both experimental and numerical investigations were conducted to analyze and model the sensing radius dependence on the probe dimensions. The results suggest that 1) the sensing radius increases linearly with the inner radius of the outer conductor and is not affected by the width of the outer conductor; 2) the inner conductor has higher impact than the insulator on the sensing radius; and 3) although the sensing radius depends on the dielectric properties of the investigated samples, the trend of the sensing radius relative to the probe dimensions is the same across different samples. Furthermore, a method for predicting the sensing radius, through use of neural networks, is proposed.

中文翻译：

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基于探头尺寸预测同轴探头的传感半径

同轴探针技术用于在微波频率范围内获取生物组织的介电特性。为了对异质样品进行介电表征，必须知道探头的感应半径。因此，在本文中，首次同时进行了实验和数值研究，以分析和模拟传感半径对探头尺寸的依赖性。结果表明：1）感应半径随外导体内径线性增加，不受外导体宽度影响；2）内导体对感应半径的影响比绝缘体大；和 3) 虽然传感半径取决于所研究样品的介电特性，不同样品的传感半径相对于探头尺寸的趋势是相同的。此外，提出了一种通过使用神经网络来预测传感半径的方法。