传输/反射法测量复介电常数的三个方程研究

介绍了利用传输／反射参数测量复介电常数的三个方程。利用奇偶模方法分析传输线与二端口网络，得到传播常数与归一化特性阻抗的解析解。进而得到确定复介电常数的三个方程。利用这些方程仅用一次测量解决已有传输／反射法中存在的低损耗材料的厚度谐振问题、多值性问题及其它问题。讨论了利用这三个方程通过一次测量解决上述问题的方法并分析了这些方程的测量不确定度。最后给出了实验结果。

Three equations for determining material complex permittivity using transmission/reflection method

Three equations for stable determination of the complex permittivity using transmission/reflection method are described by only one measurement in wide band frequencies.The analytical solutions for the normalized characteristic impedance and propagation constant in sample region were obtained by analyzing a transmission line and a two port network using an even odd mode method.Then,three equations for determining complex permittivity of a dielectric material were obtained from the normalized characteristic impedance and propagation constant and both of them,respectively.By using these three equations,the divergence observed in T/R methods available at frequencies corresponding to integer multiples of one half wavelength in the sample for a low loss material was suppressed and a multiple valued solution problem and others in the commonly used T/R methods were easily solved.The procedures for solving the above problems by only one measurement were presented and the error analysis of these three equations was performed.The experimental results were also reported.