高温超导技术在电子装备中的应用探讨

结合现代雷达应用环境和技术发展趋势,分析了高温超导在雷达装备应用的潜在优势及面临的工程和技术问题,并结合具体工程项目给出了近期迫切需要突破的关键技术。     

High Temperature Superconductivity in the Past Twenty Years Part 2——Towards to Practical Applications

After discovering high temperature superconducting materials 20 years ago, the preparation of applicable HTS materials has been pursued along with HTS mechanism and characteristic study. At present, the focus on the applied HTS technology has been moving to the industrial preparations from the laboratory research stage, and the technology has been well verified for practical applications from small to large scales. The fabrication techniques of engineering HTS materials are being industrialized; and various HTS devices are also on the way towards practical applications. This paper provides a comprehensive summary on the applied high temperature superconductivity with regard to various applicable HTS materials, their preparation techniques and charac- terization, and applications in a wide range.     

LabVIEW and PCI DAQ Card Based HTS Test and Control Platforms

This paper introduces the relevant parameters and related characteristics of the LabVIEW and PCI6221 data acquisition （DAQ） card, describes in detail the approach of building the measure and control platform of virtual instrument （VI） using LabVIEW and PCI6221, specifically discusses the system＇s application in high temperature superconductor （HTS） research including the test of HTS volt-ampere characteristics and the HTS magnetic energy storage. The experiments prove that the VI test and control system is easy to build and convenient to use.     

一种简单的高温超导连续通带双工器设计

在双抛LaAlO3衬底上外延生长的钇系高温超导薄膜YBCO的基片上,设计并制作一个四级高温超导连续通带双工器（工作频率3.0～3.5GHz和3.5～4.0GHz）,与常规金属材料的双工器相比,体积减少3/4,插损减少2dB。在液氮温区77K时,测试结果为：通带内插损小于0.8dB,通带间带外抑制大于30dB通带中心频率。为近一步研制高温超导多工器提供了很好的借鉴,对将来高温超导信道化接收机系统的研究和设计具有重要的意义。     

采用超导材料设计制作窄带宽双模微带滤波器

本文采用双面高温超导薄膜设计制作了一种窄带宽双模微带滤波器,介绍了高温超导滤波器的工作特点和性能优势,给出了四阶双模微带滤波器的设计过程、设计结果。滤波器制作于以0.5mm 厚度铝酸镧（LaAlO3）基片为衬底的双面高温超导DyBCO 薄膜上,中心频率为2017.5MHz,通带宽度为15 MHz,滤波器的测试结果与设计结果较好吻合。     

高温超导谐振器与滤波器的微调研究

高温超导滤波器采用的基底的介电常数和厚度与模拟设计值往往存在一定差异,从而导致实际制作的滤波器的中心频率和频带偏离设计值。本文提出了解决这一问题的新思路,在原有高温超导滤波器上进行微调,即对组成滤波器的每个谐振器的局部进行相同的微小结构改变,使谐振器频率偏移,进而使滤波器的整个频带发生偏移。并利用该方法对多种谐振器和四节前向耦合高温超导滤波器进行了模拟,发现数值模拟数据与理论曲线符合得很好。这一方法对于窄带高温超导滤波器尤其具有重要的意义。     

Superconducting Electronics Research at CSIRO Australia-20 Years after Discovery of HTS

CSIRO has had a long-term research effort in superconductivity, in particular, since the discovery of HTS which promised big prospects. Significant progress has been made in research and development of HTS electronic devices and systems for practical applications such as mineral and exploration as well as some niche applications in emerging science and technology areas. This article presents an overview of the CSIRO research activities in HTS superconducting electronics since 1987, outlining the HTS junction and device technology as well as various application systems develop by the group.     

Tunneling in HTS junctions

The effects caused by the layered structure of high-temperature superconductors (HTS) ought to be taken into consideration at the time of constructing different HTS junction devices. The authors demonstrate this by studying tunneling phenomena in HTS. The tunneling current-voltage characteristics of different structures such as “Normal Metal-Insulator-HTS” (NIS-structure) and “HTS-Insulator-HTS” (SIS-structure) are calculated. The real layered structure of HSS is taken into account and corresponding peculiarities on I(V) are obtained. The authors have analyzed different types of contacts which are realized in the NIS- and SIS-junctions. The contributions of the superconducting and normal layers of HTS to the tunneling current of NIS- and SIS-structures are found     

High Tc Superconductor Theoretical Models and Electromagnetic Flux Characteristics

High Tc Superconductors （HTS） have special electromagnetic characteristics and phenomena. Effort has been made in order to theoretically understand the appfied HTS superconductivity and HTS behaviors for practical appfications, various theoretical models related to the HTS electromagnetic properties have been developed. The theoretical models and analytic methods are summarized with regard to understanding the HTS magnetic flux characteristic which is one of the most critical issues related to HTS appfications such as for HTS magnetic levitation application.     

High Tc Superconductor Theoretical Models and Electromagnetic Flux Characteristics

High Tc Superconductors (HTS) have special electromagnetic characteristics and phenomena. Effort has been made in order to theoretically understand the applied HTS superconductivity and HTS behaviors for practical applications, various theoretical models related to the HTS electromagnetic properties have been developed. The theoretical models and analytic methods are summarized with regard to understanding the HTS magnetic flux characteristic which is one of the most critical issues related to HTS applications such as for HTS magnetic levitation application.     

Performance of an HTS Generator Field Coil Under System Fault Conditions

High-temperature superconducting (HTS) coils are generally stable against transient thermal disturbances. Protection against spontaneous quenches is not a main design issue for an HTS coil. However, HTS coils used in many electric devices such as motors, generators, transformers, and current limiters will operate under over-current fault conditions, which may result in a coil quench and thermal runaway. Those electric devices should be able to ride through some grid fault conditions and remain functional. This requires a certain over-current capability of the HTS coils. This paper discusses the over-current requirements from grid faults and the thermal transient responses of a BSCCO coil. It presents the analysis results of the coil subjected to over-current pulses at different operating conditions. The study also investigates the thermal runaway current and its relationship with the over-current pulse     

Analysis of magnetic field and circulating current for HTS transformer windings

In a high-temperature superconducting (HTS) transformer, the leakage magnetic field decreases the critical current and increases the ac loss in the tapes. Moreover, because of nearly zero resistance of HTS tapes, a slight unbalance of the branch inductances of the windings might result in heavy circulating current. So, the numerical analysis of the leakage magnetic field and circulating current is especially necessary for an HTS transformer design. In this paper, the influence of the winding configurations on the stray field and circulating current is studied. That is, the magnetic field distribution is analyzed by finite-element method and then, based on the inductance matrix obtained after a magnetic field analysis, the circulating current is calculated by circuit analysis. Some measures for improving the leakage field and circulating current distribution are also proposed to make HTS transformers more efficient.     

A Permanent Magnet Linear Synchronous Motor Drive for HTS Maglev Transportation Systems

A permanent magnet linear synchronous motor （PMLSM） for a high temperature superconducting （HTS） maglev system has been studied, including the motor structure, control strategy, and analysis techniques. Finite element analysis （FEA） of magnetic field is conducted to accurately calculate major motor parameters. Equivalent electrical circuit is used to predict the drive＇s steady-state characteristics, and a phase variable model is applied to predict the dynamic performance. Preliminary experiment with a prototype has been made to verify the theoretical analysis and the HTS-PM synchronous driving technology.     

高温超导微波器件应用研究进展和建议

高温超导微波技术已经成熟,在美国、欧洲等国家核心战略系统中（例如美国的全球数据传输系统）占有重要地位,在提高通信、雷达等实际系统性能中发挥了重要作用。中科院物理所的应用研究已从核心技术攻关阶段、联机试验验证阶段,进入到用户设备使用阶段。文中对我国超导研究面临的核心技术问题以及领导、规划、项目组织、研究体制等提出了建议。     

高通量卫星应用于4G基站回传的方式研究

随着电信普遍服务深入推进,4G网络将进一步拓展至山区、边疆、海岛等需要卫星通信提供传输的地区。本文分析了传统卫星应用于4G基站回传的不足,提出更应关注在传输能力与传输成本上有新突破的高通量卫星,并对高通量卫星应用于4G基站回传的方式进行了分析研究。     

Ion beam switching magnet employing HTS coils

This paper describes the design, construction, and testing of an ion beam switching high-temperature superconducting (HTS) magnet installed at Institute of Geological and Nuclear Science (IGNS) in New Zealand. It was designed by a consortium comprising American Superconductor Corporation (ASC), ISYS, Applied Engineering Technologies (AET), the New Zealand Institute for Industrial Research and Development (IRL), and Alphatech. The work was also supported in part by New Zealand Foundation for Research and Technology-Technology for Business Growth Programme. The magnet generates 0.72 T in the airgap between two 410×700 mm warm iron poles. The Bi-2223 HTS coils are conduction-cooled with a single stage Gifford-McMahon (G-M) type cryocooler for steady-state operation. The magnet was fully tested at ASC during the fall of 1996. This represents the first large-scale fully operational HTS physics magnet announced so far. The successful operation of this magnet has verified maturation of HTS magnet technology employing conduction cooling techniques with G-M type cryocoolers. Long term operation of this magnet in continuous use will prove the reliability of HTS magnet systems in critical applications and is expected to open future opportunities for HTS in other related areas     

新型高温超导(HTS)双模多次曲折微带环窄带滤波器

发展了一种新型HTS双模多次曲折微带环谐振器滤波器.给出了双模间耦合系数的精确计算方法.采用全波技术对四极滤波器特性进行的计算表明,它具有优良的窄通带、高选择性和小体积.设计、制造和测试了一个HTS四极滤波器,实验结果与理论计算基本一致.这种滤波器适用于卫星通信和移动通信系统.     

High-resistance HTS SNS edge junctions

HTS SFQ digital circuit applications require high resistance HTS Josephson junctions. We have investigated the factors affecting the resistance of SNS edge junctions which use Co-doped Y-Ba-Cu-O as the normal metal layer. Several parameters are found to have a surprisingly large effect on device resistance, including edge angle, base electrode material, and deposition conditions of the normal metal and counterelectrode. Controlling these factors has enabled the fabrication of high-quality, high-resistance (≈1 Ω) SNS edge junctions with 1-σ I_c spreads down to 10% and critical currents and I_cR_n products suitable for SFQ digital applications.     

Structural Parameter Optimization of Multilayer Conductors in HTS Cable

In this paper, the design optimization of the structural parameters of multilayer conductors in high temperature superconducting （HTS） cable is reviewed. Various optimization methods, such as the particle swarm optimization （PSO）, the genetic algorithm （GA）, and a robust optimization method based on design for six sigma （DFSS）, have been applied to realize uniform current distribution among the multilayer HTS conductors. The continuous and discrete variables, such as the winding angle, radius, and winding direction of each layer, are chosen as the design parameters. Under the constraints of the mechanical properties and critical current, PSO is proven to be a more powerful tool than GA for structural parameter optimization, and DFSS can not only achieve a uniform current distribution, but also improve significantly the reliability and robustness of the HTS cable quality.     

混合矢量有限元法分析高温超导微带线的传输特性

采用混合矢量有限元方法结合唯象二流体模型,对高温超导微带线的复电导率表达式做了推导,经Helmholtz方程弱形式变换,得到了适用于HTS微带线的方程,对高温超导(HTS)微带线的传输特性(包括损耗、色散等)进行了全波分析,与谱域法计算比照后可以发现,两者曲线在0.1GHz~1000GHz吻合很好,并采用该方法计算分析了HTS微带传输线中模式色散的影响。