A C-band high efficiency and high gain two-stage power amplifier based on A1GaN/GaN high electron mobility transistor （HEMT） is designed and measured in this paper. The input and output impedances for the optimum po...A C-band high efficiency and high gain two-stage power amplifier based on A1GaN/GaN high electron mobility transistor （HEMT） is designed and measured in this paper. The input and output impedances for the optimum power-added efficiency （PAE） are determined at the fundamental and 2nd harmonic frequency （f0 and 2f0）. The harmonic manipulation networks are designed both in the driver stage and the power stage which manipulate the second harmonic to a very low level within the operating frequency band. Then the inter-stage matching network and the output power combining network are calculated to achieve a low insertion loss. So the PAE and the power gain is greatly improved. In an operation frequency range of 5,4 GHz-5.8 GHz in CW mode, the amplifier delivers a maximum output power of 18.62 W, with a PAE of 55.15 % and an associated power gain of 28.7 dB, which is an outstanding performance.展开更多
High Te superconductor （HTS） technology has been used to develop a unique high Q resonant circuit. Such circuit or device has some special characteristics such as very high voltage generation. Theoretical study and ...High Te superconductor （HTS） technology has been used to develop a unique high Q resonant circuit. Such circuit or device has some special characteristics such as very high voltage generation. Theoretical study and experimental approaches have proceeded for the concept verification. This paper presents the theory about this high Q resonant circuit. The operation principle of the circuit is described. A practical prototype for HTS high voltage generation is also demonstrated. The experiment result shows that very high voltages can be achieved by the developed method using HTS technology.展开更多
By using 0.15 μm GaAs pHEMT （pseudomorphic high electron mobility transistor） technology,a design of millimeter wave power amplifier microwave monolithic integrated circuit （MMIC） is presented.With careful optimi...By using 0.15 μm GaAs pHEMT （pseudomorphic high electron mobility transistor） technology,a design of millimeter wave power amplifier microwave monolithic integrated circuit （MMIC） is presented.With careful optimization on circuit structure,this two-stage power amplifier achieves a simulated gain of 15.5 dB with fluctuation of 1 dB from 33 GHz to 37 GHz.A simulated output power of more than 30 dBm in saturation can be drawn from 3 W DC supply with maximum power added efficiency （PAE） of 26%.Rigorous electromagnetic simulation is performed to make sure the simulation results are credible.The whole chip area is 3.99 mm2 including all bond pads.展开更多
40 years ago, there was a revolution in power converter efficiency, density, size and cost, with the introduction of silicon MOSFETs,PWM integrated circuits(ICs),new magnetic materials and new switch-mode power topolo...40 years ago, there was a revolution in power converter efficiency, density, size and cost, with the introduction of silicon MOSFETs,PWM integrated circuits(ICs),new magnetic materials and new switch-mode power topologies.Now,another revolution is enabled with wide band-gap gallium nitride(GaN) power ICs,new control ICs,new magnetics and the commercialization of high-frequency topologies.Monolithic integration combines GaN FET,GaN logic,GaN driver and now GaN level-shifters,to enable MHz+switching without parasitic concerns.This paper introduces the AllGaN^(TM) 650 V lateral GaN technology, essential GaN power ICs features and performance across a wide range of applications, at up to 1 MHz,from 25 W to 3.2 kW.展开更多
针对变流器不同位置杂散电感准确获取困难的问题,提出一种基于LC高频振荡原理的杂散电感多参数提取方法,充分利用变流器自身结构,通过3个现场实验主动构建不同的谐振电路,并根据它们的振荡频率计算变流器不同位置的杂散电感。首先阐述...针对变流器不同位置杂散电感准确获取困难的问题,提出一种基于LC高频振荡原理的杂散电感多参数提取方法,充分利用变流器自身结构,通过3个现场实验主动构建不同的谐振电路,并根据它们的振荡频率计算变流器不同位置的杂散电感。首先阐述了高频振荡法的基本原理,建立了不同谐振实验的等值电路模型。然后,以1700 V/450 A IGBT变流器系统为例,通过仿真与实验进行了可行性与有效性验证。最后,通过实验与传统双脉冲法进行了对比分析。研究表明:所提出的方法可有效提取变流器内不同位置的杂散电感参数,与双脉冲法提取开关杂散电感结果基本一致,精度可达纳亨级。展开更多
随着航空航天技术的快速发展,封闭腔体内的无线能量传输(Wireless Power Transmission,WPT)技术开始受到广泛关注.基于频率控制的WPT技术,可实现对电大封闭腔体(103×λ3)内的多方位传感器进行可控和高效的无线充电.电大腔体内的电...随着航空航天技术的快速发展,封闭腔体内的无线能量传输(Wireless Power Transmission,WPT)技术开始受到广泛关注.基于频率控制的WPT技术,可实现对电大封闭腔体(103×λ3)内的多方位传感器进行可控和高效的无线充电.电大腔体内的电场分布对频率的变化敏感,利用频率变化实现对封闭腔体场分布控制.实验结果表明,在S波段的1 m3腔体最高WPT传输效率为96.6%.设计的宽带整流电路实测整流效率最高为80%,整流效率高于50%的带宽为1.65 GHz.在2.401~2.495 GHz频段实现控制双接收机的不同工作状态,展现其在航空航天器等封闭空间中为传感器无线供电的应用前景.展开更多
大规模风电并网导致宽频谐振问题日渐凸显,业内多认为电缆电容效应、控制器参数变化等是导致谐振的主要因素,而关于静止无功发生器(static var generator, SVG)、风功率变化与高频谐振内在因果关系研究尚未展开。针对低风速风场系统高...大规模风电并网导致宽频谐振问题日渐凸显,业内多认为电缆电容效应、控制器参数变化等是导致谐振的主要因素,而关于静止无功发生器(static var generator, SVG)、风功率变化与高频谐振内在因果关系研究尚未展开。针对低风速风场系统高频谐振问题,首先基于谐波线性化理论,考虑功率外环作用,建立SVG和双馈风机(doubly-fed induction generator, DFIG)的序阻抗模型。其次将风速变化纳入风机变流器建模,并建立空载电缆投入时风速变化与SVG阻抗的联系。然后利用阻抗交互揭示风机变流器阻抗变化对SVG阻抗特性的影响机理,指出区域内空载电缆投入后,低风速不仅降低系统在高频的鲁棒性,而且扩大了SVG高频负阻尼范围,导致系统高频谐振风险增加。最后,基于STARSIM-HIL搭建含SVG的双馈风场电磁仿真模型,并进行软硬件在环实验。实验结果证明了理论分析的正确性。展开更多
基金Project supported by the National Key Basic Research Program of China(Grant No.2011CBA00606)Program for New Century Excellent Talents in University,China(Grant No.NCET-12-0915)the National Natural Science Foundation of China(Grant No.61334002)
文摘A C-band high efficiency and high gain two-stage power amplifier based on A1GaN/GaN high electron mobility transistor （HEMT） is designed and measured in this paper. The input and output impedances for the optimum power-added efficiency （PAE） are determined at the fundamental and 2nd harmonic frequency （f0 and 2f0）. The harmonic manipulation networks are designed both in the driver stage and the power stage which manipulate the second harmonic to a very low level within the operating frequency band. Then the inter-stage matching network and the output power combining network are calculated to achieve a low insertion loss. So the PAE and the power gain is greatly improved. In an operation frequency range of 5,4 GHz-5.8 GHz in CW mode, the amplifier delivers a maximum output power of 18.62 W, with a PAE of 55.15 % and an associated power gain of 28.7 dB, which is an outstanding performance.
文摘High Te superconductor （HTS） technology has been used to develop a unique high Q resonant circuit. Such circuit or device has some special characteristics such as very high voltage generation. Theoretical study and experimental approaches have proceeded for the concept verification. This paper presents the theory about this high Q resonant circuit. The operation principle of the circuit is described. A practical prototype for HTS high voltage generation is also demonstrated. The experiment result shows that very high voltages can be achieved by the developed method using HTS technology.
基金supported by the Innovation Fund of State Key Lab of Millimeter Waves
文摘By using 0.15 μm GaAs pHEMT （pseudomorphic high electron mobility transistor） technology,a design of millimeter wave power amplifier microwave monolithic integrated circuit （MMIC） is presented.With careful optimization on circuit structure,this two-stage power amplifier achieves a simulated gain of 15.5 dB with fluctuation of 1 dB from 33 GHz to 37 GHz.A simulated output power of more than 30 dBm in saturation can be drawn from 3 W DC supply with maximum power added efficiency （PAE） of 26%.Rigorous electromagnetic simulation is performed to make sure the simulation results are credible.The whole chip area is 3.99 mm2 including all bond pads.
文摘40 years ago, there was a revolution in power converter efficiency, density, size and cost, with the introduction of silicon MOSFETs,PWM integrated circuits(ICs),new magnetic materials and new switch-mode power topologies.Now,another revolution is enabled with wide band-gap gallium nitride(GaN) power ICs,new control ICs,new magnetics and the commercialization of high-frequency topologies.Monolithic integration combines GaN FET,GaN logic,GaN driver and now GaN level-shifters,to enable MHz+switching without parasitic concerns.This paper introduces the AllGaN^(TM) 650 V lateral GaN technology, essential GaN power ICs features and performance across a wide range of applications, at up to 1 MHz,from 25 W to 3.2 kW.
文摘针对变流器不同位置杂散电感准确获取困难的问题,提出一种基于LC高频振荡原理的杂散电感多参数提取方法,充分利用变流器自身结构,通过3个现场实验主动构建不同的谐振电路,并根据它们的振荡频率计算变流器不同位置的杂散电感。首先阐述了高频振荡法的基本原理,建立了不同谐振实验的等值电路模型。然后,以1700 V/450 A IGBT变流器系统为例,通过仿真与实验进行了可行性与有效性验证。最后,通过实验与传统双脉冲法进行了对比分析。研究表明:所提出的方法可有效提取变流器内不同位置的杂散电感参数,与双脉冲法提取开关杂散电感结果基本一致,精度可达纳亨级。
