Novel Single-Domain YBCO Materials and Devices for Telecommunications Applications

高温超导体（HTS）应用于移动的和个人通信网络中使用的高频元件，将导致频谱利用和信号滤波的实质性改进。 这项工作是一种新颖的和有效的替代薄膜合成的高温超导材料的电信应用。 采用籽晶熔融生长（SMG）方法，制备了具有超低表面电阻（0.03 m（77 K，13 GHz））的大尺寸（50 mm）单畴YBa2Cu3Ox块体材料。 这种方法的优点包括廉价和高容量的处理，易于操作的几何形状，消除晶界，更好地控制晶体取向和消除高损耗介电材料的高频组件。 本文的研究工作为研究材料参数对SMG YBa_2Cu_3O_x微波性能的影响奠定了基础。 首先，SMG方法将用于产生具有超低表面电阻的单畴结构。 其次，将建立表面电阻和材料参数之间的关系，如第二相浓度和形态，晶体取向，和氧的均匀性。 在优化这些参数后，将使用各种新方法来制造特定RF组件设计所需几何形状的材料。 最后，一个高Q值谐振器，适合包含在现有的电信系统，将被构造和测试的材料的整体性能。 该计划解决了工业应用中的基本问题和关键问题。 主要研究人员在高温超导材料加工和表征方面具有重要的专业知识，并在超导界享有盛誉。 高温超导射频组件的成功实施将彻底改变电信行业，并对美国的经济增长产生重大影响。 ***

9802281 Shi The application of high temperature superconductors (HTS) to high frequency components used in mobile and personal communication networks, will result in substantial improvements in spectrum utilization and signal filtering. The proposed work is a novel and an effective alternative to the thin film synthesis of HTS materials for telecommunications applications. Using a seeded-melt-growth (SMG) method, we have developed large ( 50 mm) single-domain YBa2Cu3Ox bulk materials with ultra-low surface resistance (0.03 m( at 77 K and 13 GHz). The advantages of this approach include inexpensive and high volume processing, easy manipulation of geometry, elimination of grain boundaries, better control of crystal orientation and the elimination of high loss dielectric materials from the high frequency components. The proposed research is a fundamental study on the effect of materials parameters on microwave properties of SMG YBa2Cu3Ox. First, the SMG method will be used to produce a single-domain structure with ultra-low surface resistance. Second, a relationship will be established between the surface resistance and materials parameters such as second phase concentration and morphology, crystal orientation, and oxygen homogeneity. Upon optimization of these parameters, various new approaches will be used to fabricate materials of required geometry for a specific RF component design. Finally, a high-Q resonator, suitable for inclusion in existing telecommunications systems, will be constructed and tested for the overall performance of the materials. The proposed program addresses both fundamental questions and critical issues in industrial applications. The principal investigators have significant expertise in HTS materials processing and characterization, and an established reputation in superconductivity community. The successful implementation of HTS RF components will revolutionize the telecommunications industry and have a strong impact on the economic growth of US. ***