The impedance characteristics of distributed amplifiers are analyzed based on T-type matching networks, and a distributed power amplifier consisting of three gain cells is proposed. Non-uniform T-type matching network...The impedance characteristics of distributed amplifiers are analyzed based on T-type matching networks, and a distributed power amplifier consisting of three gain cells is proposed. Non-uniform T-type matching networks are adopted to make the impedance of artificial transmission lines connected to the gate and drain change stage by stage gradually, which provides good impedance matching and improves the output power and efficiency. The measurement results show that the amplifier gives an average forward gain of 6 dB from 3 to 16. 5 GHz. In the desired band, the input return loss is typically less than - 9. 5 dB, and the output return loss is better than -8.5 dB. The output power at 1-dB gain compression point is from 3.6 to 10. 6 dBm in the band of 2 to 16 GHz while the power added efficiency （PAE） is from 2% to 12. 5% . The power consumption of the amplifier is 81 mW with a supply of 1.8 V, and the chip area is 0.91 mm × 0.45 mm.展开更多
A radiation hardened N channel Si power device——VDMNOSFET (Vertical Double Diffused Metal Nitride Oxide Semiconductor Field Effect Transistor) is fabricated by using a double layer (Si 3N 4 SiO 2) gate dielec...A radiation hardened N channel Si power device——VDMNOSFET (Vertical Double Diffused Metal Nitride Oxide Semiconductor Field Effect Transistor) is fabricated by using a double layer (Si 3N 4 SiO 2) gate dielectric and a self aligned heavily doped shallow P + region.The effects of ionizing radiation and transient high dose rate radiation of the power VDMNOSFET are also presented.Good radiation hardening performance is obtained,compared with the conventional power VDMOSFET.For the specified 200V VDMNOSFET,the threshold voltage shifts is only -0 5V at a Gamma dose of 1Mrad(Si) with +10V gate bias;the transconductance is degraded by 10% at a Gamma dose of 1Mrad(Si);and no burnout failures occur at the transient high dose rate of 1×10 12 rad(Si)/s.It is demonstrated that the ionizing radiation tolerance and burnout susceptibilities of the power MOSFET are improved significantly by using a double layer (Si 3N 4 SiO 2) gate dielectric and a self aligned heavily doped shallow P + region.展开更多
Electrifying the on-board subsystems of aircraft becomes an inevitable process as being faced with the environmental pollution,along with the proposed concept called more electric aircraft(MEA).With the increasing num...Electrifying the on-board subsystems of aircraft becomes an inevitable process as being faced with the environmental pollution,along with the proposed concept called more electric aircraft(MEA).With the increasing number of on-board power electronic based devices,the distribution system of the aircraft can be regarded as an onboard microgrid.As it is known that the load power electronic converters can exhibit constant power load(CPL)characteristics and reduce the system stability,it is necessary to accurately predict and enhance the system stability in designing process.This paper firstly analyzes the stability of an on-board DC microgrid with the presence of CPL.Then,discusses the reasons behind instability and proposes a control strategy to enhance system stability.Finally,the simulation results are worked out to validate the analysis and the effect of the proposed control strategy.展开更多
The equivalent two-port network model of a middle range wireless power transfer(WPT) system was presented based on strongly coupled multiple resonators. The key parameters of the WPT system include self-inductance, re...The equivalent two-port network model of a middle range wireless power transfer(WPT) system was presented based on strongly coupled multiple resonators. The key parameters of the WPT system include self-inductance, resistance, parasitic capacitance, mutual inductance and S-parameters of coils & resonators were analyzed. The impedance matching method was used to optimize load power and transmission efficiency of the multi-resonator WPT system, and the impedance matching method was realized through adjusting the distances between the coils and resonators. Experiments show that the impedance matching method can effectively improve load power and transmission efficiency for middle range wireless power transfer systems with multiple resonators, at distances up to 3 times the coil radius with efficiency more than 70% and load power also close to 3.5 W.展开更多
基金The National Natural Science Foundation of China(No.61106021)the Postdoctoral Science Foundation of China(No.2015M582541)+1 种基金the Natural Science Foundation of Higher Education Institutions of Jiangsu Province(No.15KJB510020)the Research Fund of Nanjing University of Posts and Telecommunications(No.NY215140,No.NY215167)
文摘The impedance characteristics of distributed amplifiers are analyzed based on T-type matching networks, and a distributed power amplifier consisting of three gain cells is proposed. Non-uniform T-type matching networks are adopted to make the impedance of artificial transmission lines connected to the gate and drain change stage by stage gradually, which provides good impedance matching and improves the output power and efficiency. The measurement results show that the amplifier gives an average forward gain of 6 dB from 3 to 16. 5 GHz. In the desired band, the input return loss is typically less than - 9. 5 dB, and the output return loss is better than -8.5 dB. The output power at 1-dB gain compression point is from 3.6 to 10. 6 dBm in the band of 2 to 16 GHz while the power added efficiency （PAE） is from 2% to 12. 5% . The power consumption of the amplifier is 81 mW with a supply of 1.8 V, and the chip area is 0.91 mm × 0.45 mm.
文摘A radiation hardened N channel Si power device——VDMNOSFET (Vertical Double Diffused Metal Nitride Oxide Semiconductor Field Effect Transistor) is fabricated by using a double layer (Si 3N 4 SiO 2) gate dielectric and a self aligned heavily doped shallow P + region.The effects of ionizing radiation and transient high dose rate radiation of the power VDMNOSFET are also presented.Good radiation hardening performance is obtained,compared with the conventional power VDMOSFET.For the specified 200V VDMNOSFET,the threshold voltage shifts is only -0 5V at a Gamma dose of 1Mrad(Si) with +10V gate bias;the transconductance is degraded by 10% at a Gamma dose of 1Mrad(Si);and no burnout failures occur at the transient high dose rate of 1×10 12 rad(Si)/s.It is demonstrated that the ionizing radiation tolerance and burnout susceptibilities of the power MOSFET are improved significantly by using a double layer (Si 3N 4 SiO 2) gate dielectric and a self aligned heavily doped shallow P + region.
基金supported by Ministry of Science&Technology under National Key R&D Program of China(No.2021YFE0108600)Ningbo Science and Technology Bureau under S&T Innovation 2025 Major Special Program(No.2019B10071)Key International Cooperation of National Natural Science Foundation of China(No.51920105011)。
文摘Electrifying the on-board subsystems of aircraft becomes an inevitable process as being faced with the environmental pollution,along with the proposed concept called more electric aircraft(MEA).With the increasing number of on-board power electronic based devices,the distribution system of the aircraft can be regarded as an onboard microgrid.As it is known that the load power electronic converters can exhibit constant power load(CPL)characteristics and reduce the system stability,it is necessary to accurately predict and enhance the system stability in designing process.This paper firstly analyzes the stability of an on-board DC microgrid with the presence of CPL.Then,discusses the reasons behind instability and proposes a control strategy to enhance system stability.Finally,the simulation results are worked out to validate the analysis and the effect of the proposed control strategy.
基金Project(61104088)supported by the National Natural Science Foundation of ChinaProject(12C0741)supported by Scientific Research Fund of Hunan Provincial Education Department,China
文摘The equivalent two-port network model of a middle range wireless power transfer(WPT) system was presented based on strongly coupled multiple resonators. The key parameters of the WPT system include self-inductance, resistance, parasitic capacitance, mutual inductance and S-parameters of coils & resonators were analyzed. The impedance matching method was used to optimize load power and transmission efficiency of the multi-resonator WPT system, and the impedance matching method was realized through adjusting the distances between the coils and resonators. Experiments show that the impedance matching method can effectively improve load power and transmission efficiency for middle range wireless power transfer systems with multiple resonators, at distances up to 3 times the coil radius with efficiency more than 70% and load power also close to 3.5 W.
