微波谐振腔微扰法测量材料介电常数的精度分析

Analyses of Microwave Perturbation Technology for Measuring Material Permittivity

基于微波谐振腔微扰技术,利用有限元分析软件ANSYS、腔体微扰精确解方程和近似解公式,分析了材料尺寸、形状和介电常数大小对材料介电常数测量精度的影响。仿真结果表明,当材料介电常数和样品尺寸较小时,以上3种方法得到的结果相同,否则,测量误差极大。因此,必须针对材料形状和不同介电常数范围设计微波谐振腔,才能保证材料介电常数的测量精度。

Based on microwave cavity perturbation techniques, the accuracy of permittivity measurement for materials are investigated, as a function of the size, shape and dielectric constant of the material. It is discovered that when the size and dielectric constant of a material are relatively small, the results are identical. Outside of this qualification, errors in measurements arise. Therefore, in order to improve measurement accuracy, microwave cavities should be designed according to the shapes and permittivity of the material to be processes therein.