摘要
介电特性是研究物料的微波特性和设计物料微波器件的关键参数。本文使用无校准同轴传输反射法测量三七粉的微波介电特性,为三七粉微波鉴定、微波杀菌、微波干燥提供依据。实验分析了9%～42%含水率下文山三七粉在微波频段2 GHz～5 GHz间的介电特性,拟合得到三七粉的介电常数(ε′)、介电损耗因子(ε″)和损耗角正切(tanδ)随含水率(M)、微波频率(F)变化的经验公式。结果表明,随着频率的增加,同一含水率三七粉的ε′和ε″单调递减变化,含水率越高的样品递减幅度越大;随着含水率的增加,同一频率下三七粉的ε′、ε″和tanδ单调递增变化,递增幅度为ε′>ε″> tanδ。本实验方法也可用于测定其它药用粉末物料的微波介电特性。
Dielectric properties are important parameters to study microwave characteristics of materials and design microwave devices.This paper uses T-matrix-based coaxial transmission method based on the reflection,which need not to be calibrated and is proposed to measure dielectric properties of pseudo-ginseng powder,and provides the basis for microwave identification,microwave sterilization and microwave drying of pseudo-ginseng powder.An experimental analysis has been carried out to study dielectric properties of Wenshan pseudo-ginseng powder with different moisture contents(9%~42%) within frequency range 2 GHz^5 GHz.Empirical formulas about the relations of dielectric properties with moisture contents and microwave frequency of pseudo-ginseng powder have been obtained by the fitting method.The results show that with the increase of frequency,the dielectric constant(ε′) and dielectric loss factor(ε″) of pseudo-ginseng powder monotonically decrease under the same moisture content,and the higher moisture content of sample,the higher decreasing rate.With the increase of moisture content,the dielectric constant(ε′),dielectric loss factor(ε″) and loss tangent(tan δ)of pseudo-ginseng powder monotonically increase under the same frequency,and increment rate is ε′ > ε″ > tan δ.Experimental method could be applied to measure dielectric properties of other medicinal powder materials.
作者
钟汝能
姚斌
向泰
ZHONG Runeng;YAO Bin;XIANG Tai(School of Energy and Environmental Science, Yunnan Normal University, Kunming 650500, China;School of Physics and Electronic Information, Yunnan Normal University, Kunming 650500, China)
出处
《文山学院学报》
2018年第6期44-48,共5页
Journal of Wenshan University
基金
云南省科技计划面上项目"大型高温微波反应器中热点及热失控问题研究"(2014FB141)
关键词
同轴传输反射法
三七粉
介电特性
含水率
微波
coaxial transmission and reflection method
pseudo-ginseng powder
dielectric properties
moisture Content
microwave
