基于微波透射法的谷物粉相对介电常数检测装置设计  

Design of Grain Powder Dielectric Constant Detection Device Based on Microwave Transmission Method

作　　者：白雪[1] 倪利华 徐雷钧[1] BAI Xue;NI Lihua;XU Leijun(School of Electrical Information Engineering,Jiangsu University,Zhenjiang 212013,China)

机构地区：[1]江苏大学电气信息工程学院,镇江212013

出　　处：《微波学报》2024年第2期40-45,50,共7页Journal of Microwaves

摘　　要：针对谷物属性的快速测量需求,设计了一种小型化的谷物粉相对介电常数快速检测装置。创新性地提出了一种双外差混频结构,并基于自由空间法建立了微波相移量与谷物粉相对介电常数的关系。通过对米粉、大麦粉和糯米粉在4.5 GHz~11.5 GHz频率范围内进行测量,计算出相对介电常数,采用随机森林算法进行种类鉴别。实验结果表明,相对介电常数平均相对误差不超过3.5%,样品预测正确率为96.7%,检测装置具有良好的可重复性和实用性。A miniaturized rapid detection device for relative dielectric constant of grain powder is designed for the need of rapid measurement of grain properties.An innovative double heterodyne mixing structure is proposed.The relationship between the microwave phase shift and the relative dielectric constant of grain powder is established based on the free-space method.The relative dielectric constants are calculated by measuring rice flour,barley flour and glutinous rice flour in the frequency range from 4.5 GHz to 11.5 GHz,and the random forest algorithm is used for species identification.The experimental results show that the average relative error of the relative dielectric constant does not exceed 3.5%,the sample prediction accuracy is 96.7%,and the detection device has good repeatability and practicability.

关 键 词：微波 谷物粉 介电常数 随机森林 

分 类 号：TS210.7[轻工技术与工程—粮食、油脂及植物蛋白工程]