基于带线环行器的工作原理,使用YIG软磁基片设计并制作了一款双Y结环行器,工作中心频率及工作范围分别是8.5 GHz,7 GHz^10 GHz.使用HFSS进行仿真设计,环行器的插入损耗小于0.26 d B,反射损耗和隔离度均大于21 d B,具有良好的宽带特性....基于带线环行器的工作原理,使用YIG软磁基片设计并制作了一款双Y结环行器,工作中心频率及工作范围分别是8.5 GHz,7 GHz^10 GHz.使用HFSS进行仿真设计,环行器的插入损耗小于0.26 d B,反射损耗和隔离度均大于21 d B,具有良好的宽带特性.使用矢量网络分析仪测试了环行器样品,测试结果和仿真结果基本相符,在6.7 GHz^8.1 GHz频段内插损小于0.78 d B,在7.0 GHz^8.6 GHz频段内隔离度大于17 d B.展开更多
铁氧体隔离器在微波系统中具有重要作用。基于YIG铁氧体基片,采用低场工作模式和双Y圆盘中心导体结构,设计了一款X波段隔离器,通过三维电磁仿真软件HFSS仿真分析了不同参数对隔离器性能的影响并进行了优化,进行加工测试。测试结果表明,...铁氧体隔离器在微波系统中具有重要作用。基于YIG铁氧体基片,采用低场工作模式和双Y圆盘中心导体结构,设计了一款X波段隔离器,通过三维电磁仿真软件HFSS仿真分析了不同参数对隔离器性能的影响并进行了优化,进行加工测试。测试结果表明,在9.2~9.8 GHz的频率范围内,电压驻波比（VSWR）〈1.1 d B,插入损耗〈0.5 d B,隔离度〉23d B,所设计的隔离器达到了较高的性能指标,符合微波射频电路高频段、高性能的要求。展开更多
Cathode materials Li[CoxNiyMn1-x-y]O2 for lithium secondary batteries have been prepared by a new route using layered double hydroxides （LDHs） as a precursor. The resulting layered phase with the α- NaFe02 structur...Cathode materials Li[CoxNiyMn1-x-y]O2 for lithium secondary batteries have been prepared by a new route using layered double hydroxides （LDHs） as a precursor. The resulting layered phase with the α- NaFe02 structure crystallizes in the rhombohedral system, with space group R-3m having an interlayer spacing close to 0.47 nm. X-ray photoelectron spectroscopy （XPS） was used to measure the oxidation states of Co, Ni and Mn. The effects of varying the Co[Ni[Mn ratio on both the structure and electrochemical properties of Li[CoxNiyMn1-x-y]O2 have been investigated by X-ray diffraction and electrochemical tests. The products demonstrated a rather stable cycling behavior, with a reversible capacity of 118 mAh/g for the layered material with Co/Ni/Mn = 1/1/1.展开更多
文摘基于带线环行器的工作原理,使用YIG软磁基片设计并制作了一款双Y结环行器,工作中心频率及工作范围分别是8.5 GHz,7 GHz^10 GHz.使用HFSS进行仿真设计,环行器的插入损耗小于0.26 d B,反射损耗和隔离度均大于21 d B,具有良好的宽带特性.使用矢量网络分析仪测试了环行器样品,测试结果和仿真结果基本相符,在6.7 GHz^8.1 GHz频段内插损小于0.78 d B,在7.0 GHz^8.6 GHz频段内隔离度大于17 d B.
文摘铁氧体隔离器在微波系统中具有重要作用。基于YIG铁氧体基片,采用低场工作模式和双Y圆盘中心导体结构,设计了一款X波段隔离器,通过三维电磁仿真软件HFSS仿真分析了不同参数对隔离器性能的影响并进行了优化,进行加工测试。测试结果表明,在9.2~9.8 GHz的频率范围内,电压驻波比（VSWR）〈1.1 d B,插入损耗〈0.5 d B,隔离度〉23d B,所设计的隔离器达到了较高的性能指标,符合微波射频电路高频段、高性能的要求。
基金supported by the National Natural Science Foun-dation of China, the 111 Project (grant no.: B07004) the Natural Science Foundation for Young Teachers of Beijing University of Chemical Technology (grant no.: QN0723)
文摘Cathode materials Li[CoxNiyMn1-x-y]O2 for lithium secondary batteries have been prepared by a new route using layered double hydroxides （LDHs） as a precursor. The resulting layered phase with the α- NaFe02 structure crystallizes in the rhombohedral system, with space group R-3m having an interlayer spacing close to 0.47 nm. X-ray photoelectron spectroscopy （XPS） was used to measure the oxidation states of Co, Ni and Mn. The effects of varying the Co[Ni[Mn ratio on both the structure and electrochemical properties of Li[CoxNiyMn1-x-y]O2 have been investigated by X-ray diffraction and electrochemical tests. The products demonstrated a rather stable cycling behavior, with a reversible capacity of 118 mAh/g for the layered material with Co/Ni/Mn = 1/1/1.
