基于InGaP/GaAs异质结双极晶体管（HBT）工艺设计了一款X波段低相噪单片集成压控振荡器（VCO）,该VCO采用Colpitts双推（push-push）电路结构,芯片上集成了负阻振荡电路、分布式谐振器、变容二极管和耦合输出电路。通过优化HBT器件尺寸...基于InGaP/GaAs异质结双极晶体管（HBT）工艺设计了一款X波段低相噪单片集成压控振荡器（VCO）,该VCO采用Colpitts双推（push-push）电路结构,芯片上集成了负阻振荡电路、分布式谐振器、变容二极管和耦合输出电路。通过优化HBT器件尺寸以降低其引入的1/f噪声,同时设计高Q值分布式谐振电路,从而有效降低了VCO的输出相位噪声。通过采用背靠背变容二极管对来增加VCO输出频率调谐带宽。测试结果表明,所设计芯片在5 V供电时的电流约180 m A,电调电压在1-13 V变化下输出频率覆盖8.8-10 GHz,典型输出功率为10 d Bm,单边带相位噪声为-115 d Bc/Hz@100 k Hz。芯片尺寸为2.5 mm×1.6 mm。展开更多
The rods that were shaped from nanocrystalline WC- 10.21 Co-0.42 VC/ Cr3 C2 （ wt% ） composite powders by using powder extrusion molding （PEM） were investigated. The nanocrystalline WC- 10.21 Co- 0. 42 VC/ Cr3 C2 ...The rods that were shaped from nanocrystalline WC- 10.21 Co-0.42 VC/ Cr3 C2 （ wt% ） composite powders by using powder extrusion molding （PEM） were investigated. The nanocrystalline WC- 10.21 Co- 0. 42 VC/ Cr3 C2 （ wt% ） composite powders were prepared by the spray thermal decomposition-continuous reduction and carburization technology. In order to improve the properties of rods shaped by using powder extrusion molding, the cold isostatic pressing （CIP） technology was used before or after debinding. Specimens were siutered by vacuum siutering and hot isostatic pressing （HIP）. The density, Rockwell A hardness, magnetic coercivity , and magnetic saturation induction of siutered specimen were measured. The microstructure of the green bodies and the siutered specimens was studied by scanning electron microscopy （SEM）. Results show that the rod formed by using powder extrusion molding after debinding and followed by cold isostatic pressing can be siutered to 99.5% density of composite cemented carbide rods with an average grain size of about 200- 300 nm, magnetic coercivity of 30.4 KA / m, Rockwell A hardness of 92.6 and magnetic saturation induction of 85% . Superfine WC- 10 Co cemented carbide rods with excellent properties were obtained.展开更多
文摘基于InGaP/GaAs异质结双极晶体管（HBT）工艺设计了一款X波段低相噪单片集成压控振荡器（VCO）,该VCO采用Colpitts双推（push-push）电路结构,芯片上集成了负阻振荡电路、分布式谐振器、变容二极管和耦合输出电路。通过优化HBT器件尺寸以降低其引入的1/f噪声,同时设计高Q值分布式谐振电路,从而有效降低了VCO的输出相位噪声。通过采用背靠背变容二极管对来增加VCO输出频率调谐带宽。测试结果表明,所设计芯片在5 V供电时的电流约180 m A,电调电压在1-13 V变化下输出频率覆盖8.8-10 GHz,典型输出功率为10 d Bm,单边带相位噪声为-115 d Bc/Hz@100 k Hz。芯片尺寸为2.5 mm×1.6 mm。
基金Funded by Open Foundation of State Key Laboratory of AdvancedTechnologyfor Materials Synthesis and Processing, Wuhan Universi-ty of Technology, the Post PhD Science Foundation of China(2003034504) andthe Foundation of Wuhan University of Technol-ogy(2003XJJ202)
文摘The rods that were shaped from nanocrystalline WC- 10.21 Co-0.42 VC/ Cr3 C2 （ wt% ） composite powders by using powder extrusion molding （PEM） were investigated. The nanocrystalline WC- 10.21 Co- 0. 42 VC/ Cr3 C2 （ wt% ） composite powders were prepared by the spray thermal decomposition-continuous reduction and carburization technology. In order to improve the properties of rods shaped by using powder extrusion molding, the cold isostatic pressing （CIP） technology was used before or after debinding. Specimens were siutered by vacuum siutering and hot isostatic pressing （HIP）. The density, Rockwell A hardness, magnetic coercivity , and magnetic saturation induction of siutered specimen were measured. The microstructure of the green bodies and the siutered specimens was studied by scanning electron microscopy （SEM）. Results show that the rod formed by using powder extrusion molding after debinding and followed by cold isostatic pressing can be siutered to 99.5% density of composite cemented carbide rods with an average grain size of about 200- 300 nm, magnetic coercivity of 30.4 KA / m, Rockwell A hardness of 92.6 and magnetic saturation induction of 85% . Superfine WC- 10 Co cemented carbide rods with excellent properties were obtained.
