高温超导薄膜微波表面电阻的测量

【作者】 黎涛；

【导师】 张其劭；

【作者基本信息】 电子科技大学 ， 物理电子学， 2003， 硕士

【摘要】 本论文是国家863项目下达的课题。高温超导薄膜制备技术的不断提高使得薄膜的应用日益广泛，因而对薄膜各种性能指标的测定也显得更加重要，这就迫切需要对超导薄膜最主要的微波特性参数－微波表面电阻进行精确的测试。本文就对超导薄膜的微波表面电阻的测试进行了系统的研究。本文介绍了一种利用TE011+δ模式的蓝宝石介质谐振器测量高温超导薄膜微波表面电阻的方法，通过测量加载超导薄膜前后介质谐振腔的固有品质因数的变化来确定超导薄膜的微波表面电阻。这种方法能够准确地测量高温超导薄膜的微波表面电阻，而且能对单片薄膜进行非损伤地测量。本文在前人的研究基础上，改进制作了一个工作在17GHz附近的蓝宝石介质谐振腔测试座，分析了谐振回路的耦合及外电路的匹配问题，并构建了自动测试系统。利用该测试系统可对高温超导薄膜的微波表面电阻进行测试，它具有灵敏度高，重复性好，对薄膜无损伤等特点。本文还对在校准过程中可能出现的非镜像对称性因素进行了系统的分析，总结了这些因素对测试结果可能的影响，并提出了消除这些因素的方法。更多还原

【Abstract】 This paper is one of the 863 projects.As the manufacture technology of high temperature superconductor (HTSC) film is greatly improved, it is applied more and more widely. Then it is becoming urgent to precisely measure the surface resistance of HTSC film that is one of the most important parameters of HTSC film. In this paper we will research the measurement in details.Sapphire resonator working in TE011+δ mode is used in this paper to nondestructively measure the microwave surface resistance RS of a single piece of HTS thin film at 77K.The microwave surface of HTSC film under test can be determined by measuring the change of the unloaded quality factors of the loaded resonator.Based on the others’ research, a sapphire resonator working at 12GHz was improved and fabricated. The coupling of resonant circuit and the match of the outside circuit are analyzed. And the automatic test system is also built. The system features high sensitivity, good repeatability and nondestructive test. In this paper we also analyze the factors which will destroy the symmetry and bring forward some suggestion to reduce the nonsymmetry.更多还原