芋头的介电特性

Research of Dielectric Properties of Taro

利用矢量网络分析仪和末端开路的同轴探头,测量了30~3 000 MHz频段内含水(以质量分数表示)分别为25%、40%、55%、70%、85%的芋头片在20、40、60℃和80℃下的介电特性。研究表明:介电常数与介质损耗因子随频率的增加而降低,介电常数随着含水率的增大而增大;介电常数与介质损耗因子都随着温度的升高而减小;915 MHz下介电常数与介质损耗因子的数学模型的显著水平均小于0.000 1,可预测芋头的含水率;同一含水率与温度的芋头片穿透深度随频率的增加而降低,一定频率下的芋头片的穿透深度随温度的增加而增加。

The dielectric properties of taro slices with different moisture content from 25%to 85%at 20,40,60℃and 80℃are measured by the open-ended coaxial-line probe and a network analyzer from 30 to 3 000 MHz.The results show that dielectric constant and dielectric loss factor decrease with the increase of frequency,the dielectric constant increase with the increase of moisture content.the dielectric constant and dielectric loss factor of taro decrease with the increase of temperature.Under the condition of 915 MHz,the mathematical model's levels of significance of dielectric constant and dielectric loss factor are both less than 0.000 1,this result can predict the moisture content of the taro.the taro intake depth of the same moisture content and temperature decreases with the increase frequency,the taro intake depth increases with the increase of temperature under a certain frequency.