Nondestructive Electrical Characterization of Materials at Microwave Frequencies

这项研究旨在开发合适的测量方法和相关的计算机软件，以无损地表征材料在超高频和微波频率下的复介电常数。将使用一条开放的同轴线来测量介电常数。地面上同轴开口的孔径阻抗的定常变分公式将被用来将其输入反射系数与样品介质的电学性质联系起来。首先，将考虑大样本媒体。薄介质片材料将在后面讨论。用傅里叶变换的方法来求解介质薄片材料的情况，并考虑了表面波激励的可能性。

This research is directed towards developing suitable measurement methods and related computer software for nondestructive characterization of the complex permittivity of materials at UHF and microwave frequencies. An open-ended coaxial line will be used to make permittivity measurements. A stationary variational formulation for the aperture impedance of the coaxial opening on a ground plane will be used to relate its input reflection coefficient with the electrical properties of the sample medium. To start with, large sample media will be considered. Thin dielectric sheet materials will be considered later. The fourier transform method will be used to solve the case of thin dielectric sheet materials, and possibilities of the surface wave excitation will be considered.