Based on the minimum settling time （MST） theory and step-response analysis of the second order system in active switched capacitor （SC） networks, a novel clock feedthrough frequency compensation （CFFC） method fo...Based on the minimum settling time （MST） theory and step-response analysis of the second order system in active switched capacitor （SC） networks, a novel clock feedthrough frequency compensation （CFFC） method for a folded-cascode OTA is proposed. The damping factor r/is adjusted by using MOS capacitors to introduce clock feedthrough so that the OTA can obtain the MST state and thus achieve fast settling. Research results indicate that the settling time of the compensated OTA is reduced by 22.7% ;as the capacitor load varies from 0.5 to 2.5pF,the improved settling time increases approximately linearly from 3.62 to 4.46ns： for VGA application, fast settling can also be achieved by modifying the MOS capacitor value accordingly when the closed loop gain of the compensated OTA varies.展开更多
Detailed design of the vacuum feedthrough for the ion cyclotron radio frequency （ICRF） antenna in EAST, along with an electro-analysis and thermal structural analysis, is pre- sented. The electric field, the voltage...Detailed design of the vacuum feedthrough for the ion cyclotron radio frequency （ICRF） antenna in EAST, along with an electro-analysis and thermal structural analysis, is pre- sented. The electric field, the voltage standing wave ratio （VSWR） and the stresses in the vacuum feedthrough are studied. A method using the rings of oxygen-free copper as the cushion and macro- beam plasma arc welding is applied in the assembly to protect the ceramic from being damaged during welding. The vacuum leak test on the prototype of vacuum feedthrough is introduced.展开更多
The heat transfer characteristics of feedthrough flange under high alternating current excitation were investigated by threedimensional finite element model.The correlations between the heat transfer behaviors and sys...The heat transfer characteristics of feedthrough flange under high alternating current excitation were investigated by threedimensional finite element model.The correlations between the heat transfer behaviors and system parameters including applied current,ceramic thickness and working time were discussed comprehensively.A remarkable absorbed power beyond 100 W in flange would be produced by the electromagnetic field from wires.Under natural cooling condition,there is an obvious temperature rise about 40℃in the flange center after 10 min of current excitation.Three types of water cooling solutions acting on flange surface,e.g.line type,circle type and S type solutions,were proposed to reduce the flange temperature under high alternating current and long working time condition.By the S type water cooling mode,the best cooling effect can be achieved that the maximum temperature rise is about 20℃and the average temperature rise is less than 5℃.展开更多
Purpose Based on the requirements of the High Energy Photon Source(HEPS),the key components for strip-type and button-type beam position monitors(BPMs)and feedthroughs are designed and manufactured.Method The mechanic...Purpose Based on the requirements of the High Energy Photon Source(HEPS),the key components for strip-type and button-type beam position monitors(BPMs)and feedthroughs are designed and manufactured.Method The mechanical structure of the feedthroughs is designed according to the Computer Simulation Technology(CST)simulation results.Resultsandconclusions Small batches of feedthroughs are manufactured,and the structure is optimized based on mechanical,vacuum,electromagnetic,and other characteristic test results.The performance improved significantly owing to optimization through batch product testing,and quality control-related information from several manufacturers is obtained,which provide a foundation for the development of BPMs for HEPS.展开更多
文摘Based on the minimum settling time （MST） theory and step-response analysis of the second order system in active switched capacitor （SC） networks, a novel clock feedthrough frequency compensation （CFFC） method for a folded-cascode OTA is proposed. The damping factor r/is adjusted by using MOS capacitors to introduce clock feedthrough so that the OTA can obtain the MST state and thus achieve fast settling. Research results indicate that the settling time of the compensated OTA is reduced by 22.7% ;as the capacitor load varies from 0.5 to 2.5pF,the improved settling time increases approximately linearly from 3.62 to 4.46ns： for VGA application, fast settling can also be achieved by modifying the MOS capacitor value accordingly when the closed loop gain of the compensated OTA varies.
文摘Detailed design of the vacuum feedthrough for the ion cyclotron radio frequency （ICRF） antenna in EAST, along with an electro-analysis and thermal structural analysis, is pre- sented. The electric field, the voltage standing wave ratio （VSWR） and the stresses in the vacuum feedthrough are studied. A method using the rings of oxygen-free copper as the cushion and macro- beam plasma arc welding is applied in the assembly to protect the ceramic from being damaged during welding. The vacuum leak test on the prototype of vacuum feedthrough is introduced.
基金supported by the National Natural Science Foundation of China(Grant Nos.51734008,51522102,51327901 and 51474175)the National Key R&D Program of China(Grant No.2018YFB2001800)the Shannxi Key Industry Chain Program(Grant No.2019ZDLGY05-10)。
文摘The heat transfer characteristics of feedthrough flange under high alternating current excitation were investigated by threedimensional finite element model.The correlations between the heat transfer behaviors and system parameters including applied current,ceramic thickness and working time were discussed comprehensively.A remarkable absorbed power beyond 100 W in flange would be produced by the electromagnetic field from wires.Under natural cooling condition,there is an obvious temperature rise about 40℃in the flange center after 10 min of current excitation.Three types of water cooling solutions acting on flange surface,e.g.line type,circle type and S type solutions,were proposed to reduce the flange temperature under high alternating current and long working time condition.By the S type water cooling mode,the best cooling effect can be achieved that the maximum temperature rise is about 20℃and the average temperature rise is less than 5℃.
基金funded by the Youth Innovation Promotion Association CAS(Nos.2019013 and Y202005)the National Natural Science Foundation of China(No.11975254).
文摘Purpose Based on the requirements of the High Energy Photon Source(HEPS),the key components for strip-type and button-type beam position monitors(BPMs)and feedthroughs are designed and manufactured.Method The mechanical structure of the feedthroughs is designed according to the Computer Simulation Technology(CST)simulation results.Resultsandconclusions Small batches of feedthroughs are manufactured,and the structure is optimized based on mechanical,vacuum,electromagnetic,and other characteristic test results.The performance improved significantly owing to optimization through batch product testing,and quality control-related information from several manufacturers is obtained,which provide a foundation for the development of BPMs for HEPS.
