标题：Nondestructive and Noncontact Dielectric Measurement Methods for Transformer Oil Using Free-space Microwave Measurement System in 19 � 25 GHz Frequency Range
期刊名称：International Journal on Computer Science and Engineering
印刷版ISSN：2229-5631
电子版ISSN：0975-3397
出版年度：2010
卷号：2
期号：4
页码：1184-1189
出版社：Engg Journals Publications
摘要：Nondestructive, noncontact and real time evaluation of dielectric properties of low-loss liquids are important for applications such as service-aged transformer oil, biomedical, remote sensing and design of radar absorbing material. Free-space methods were developed to measure dielectric properties of low-loss liquids at microwave frequencies. Metal-back method was developed for Free-space Microwave Measurement system (FSMM). The purpose of this research is to measure the dielectric properties of transformer oil by using free-space microwave measurement system between 18 � 26 GHz (K-band), to compare measured results with published results for transformer oil and to collect the variation values of dielectric properties in microwave frequency between 18GHz to 26GHz (k-band). FSMM system consists of spot focusing horn lens antennas, mode transitions, coaxial cables and vector network analyzer (VNA). Dielectric constants and loss factors were measured for new transformer oil and all results close agreed with published data. It is observed that metal-back method is suitable for dielectric measurement of transformer oil.
关键词：Nondestructive; Noncontact; Metal back; Horn antennas; Coaxial; Microwave; Transformer oil.
