Design and characterization of a G-band（140–220 GHz） terahertz monolithic integrated circuit（TMIC） amplifier in eight-stage common-emitter topology are performed based on the 0.5-μm In Ga As/In P double heteroju...Design and characterization of a G-band（140–220 GHz） terahertz monolithic integrated circuit（TMIC） amplifier in eight-stage common-emitter topology are performed based on the 0.5-μm In Ga As/In P double heterojunction bipolar transistor（DHBT）. An inverted microstrip line is implemented to avoid a parasitic mode between the ground plane and the In P substrate. The on-wafer measurement results show that peak gains are 20 dB at 140 GHz and more than 15-dB gain at 140–190 GHz respectively. The saturation output powers are-2.688 dBm at 210 GHz and-2.88 dBm at 220 GHz,respectively. It is the first report on an amplifier operating at the G-band based on 0.5-μm InP DHBT technology. Compared with the hybrid integrated circuit of vacuum electronic devices, the monolithic integrated circuit has the advantage of reliability and consistency. This TMIC demonstrates the feasibility of the 0.5-μm InGaAs/InP DHBT amplifier in G-band frequencies applications.展开更多
A common base four-finger InOaAs/InP double heterojunction bipolar transistor with 535 OHz fmax by using the 0.5 μm emitter technology is fabricated. Multi-finger design is used to increase the input current. Common ...A common base four-finger InOaAs/InP double heterojunction bipolar transistor with 535 OHz fmax by using the 0.5 μm emitter technology is fabricated. Multi-finger design is used to increase the input current. Common base configuration is compared with common emitter configuration, and shows a smaller K factor at high frequency span, indicating a larger breakpoint frequency of maximum stable gain/maximum available gain （MSG/MAG） and thus a higher gain near the cut-off frequency, which is useful in THz amplifier design.展开更多
A physical model for scaling and optimizing InGaAs/InP double heterojunction bipolar transistors（DHBTs） based on hydrodynamic simulation is developed.The model is based on the hydrodynamic equation,which can accurat...A physical model for scaling and optimizing InGaAs/InP double heterojunction bipolar transistors（DHBTs） based on hydrodynamic simulation is developed.The model is based on the hydrodynamic equation,which can accurately describe non-equilibrium conditions such as quasi-ballistic transport in the thin base and the velocity overshoot effect in the depleted collector.In addition,the model accounts for several physical effects such as bandgap narrowing,variable effective mass,and doping-dependent mobility at high fields.Good agreement between the measured and simulated values of cutoff frequency,f t,and maximum oscillation frequency,f max,are achieved for lateral and vertical device scalings.It is shown that the model in this paper is appropriate for downscaling and designing InGaAs/InP DHBTs.展开更多
Background: Although treatment guidelines for bipolar disorder in many countries commonly include lithium carbonate joint with sodium valproate, this combination is not effective for all patients. Moreover, some adver...Background: Although treatment guidelines for bipolar disorder in many countries commonly include lithium carbonate joint with sodium valproate, this combination is not effective for all patients. Moreover, some adverse reactions related to this treatment, neurotoxicity and interaction with other drugs justify and call for a new reviewing of the issue. Methods: Evidence base for the interactions of combined drugs, the metabolic features, action mechanism, efficacy and side effects of these treatment combinations were reviewed. Considerable attention was given to the relationship of the mutual action of these drugs with their clinical efficacy but also their side effects. Results: The efficacy of combination therapy of lithium with valproate for treatment and prevention of mania were superior to monotherapy of lithium or valproate. Conclusion: Double mood stabilizer therapy is the best relative treatment for patients with bipolar disorder, especially mania and related episodes.展开更多
基于模块化多电平换流器的高压柔性直流输电系统(modular multilevel converter-based high voltage direct current,MMC-HVDC)常采用双极接线方式以提高系统功率输送能力和可靠性。然而目前对于风电场经柔直外送系统的稳定性研究集中...基于模块化多电平换流器的高压柔性直流输电系统(modular multilevel converter-based high voltage direct current,MMC-HVDC)常采用双极接线方式以提高系统功率输送能力和可靠性。然而目前对于风电场经柔直外送系统的稳定性研究集中于单极接线方式,孤岛直驱风电场与采用不同双极协调控制的双极MMC-HVDC互联系统小信号稳定性问题还有待进一步探究。该文首先考虑频率耦合特性、参考系初相位和直流侧耦合特性的影响,分别建立了采用双U/f下垂控制和定U/f-P/Q控制的双极MMC-HVDC系统交流侧等效SISO阻抗模型,并详细分析了金属回线阻抗和双极间功率均分度对交流阻抗特性的影响。接着对比研究了两种协调控制中共有控制环路和特有控制环路对交流侧负电阻特性及互联系统稳定性的影响规律。最后,孤岛直驱风电场经两种双极协调控制下双极MMC-HVDC外送系统Matlab/Simulink时域仿真结果和硬件在环半实物实时仿真实验结果验证了所提出的小信号阻抗模型的精确性和稳定性分析结论的有效性。展开更多
By deriving the discrete-time models of a digitally controlled H-bridge inverter system modulated by bipolar sinu- soidal pulse width modulation （BSPWM） and unipolar double-frequency sinusoidal pulse width modulati...By deriving the discrete-time models of a digitally controlled H-bridge inverter system modulated by bipolar sinu- soidal pulse width modulation （BSPWM） and unipolar double-frequency sinusoidal pulse width modulation （UDFSPWM） respectively, the performances of the two modulation strategies are analyzed in detail. The circuit parameters, used in this paper, are fixed. When the systems, modulated by BSPWM and UDFSPWM, have the same switching frequency, the stabil- ity boundaries of the two systems are the same. However, when the equivalent switching frequencies of the two systems are the same, the BSPWM modulated system is more stable than the UDFSPWM modulated system. In addition, a convenient method of establishing the discrete-time model of piecewise smooth system is presented. Finally, the analytical results are confirmed by circuit simulations and experimental measurements.展开更多
二极管中点钳位NPC(neutral point clamped)三电平逆变器具备较低的开关应力、谐波分量和较好的抗干扰能力,促使其成为光伏、储能等新能源领域DC-AC变换器的主要拓扑之一。针对大功率应用场景中普遍采用的NPC三电平IGBT功率半导体模块...二极管中点钳位NPC(neutral point clamped)三电平逆变器具备较低的开关应力、谐波分量和较好的抗干扰能力,促使其成为光伏、储能等新能源领域DC-AC变换器的主要拓扑之一。针对大功率应用场景中普遍采用的NPC三电平IGBT功率半导体模块开展研究,分析NPC三电平功率模块的换流回路,并据此给出对应换流回路的寄生参数精准仿真评估方法。依据换流回路寄生参数最小原则,设计适用于NPC三电平功率半导体模块的动态特性测试电路。根据换流回路以及电路工作原理,设计NPC三电平功率模块的驱动电路,并给出增强驱动电流、防直通及死区时间可调的驱动方案。最后,通过对NPC三电平IGBT模块的动态测试,详细评估了不同工况下功率器件的动态损耗。展开更多
随着模块化多电平换流器直流输电(modular multilevel converter based HVDC,MMC-HVDC)的快速发展,远距离大容量架空线直流输电系统随之出现。相比于电缆线路,架空线输电易发生短路、闪络等瞬时故障,必须采取相应措施限制故障电流,避免...随着模块化多电平换流器直流输电(modular multilevel converter based HVDC,MMC-HVDC)的快速发展,远距离大容量架空线直流输电系统随之出现。相比于电缆线路,架空线输电易发生短路、闪络等瞬时故障,必须采取相应措施限制故障电流,避免系统停运。针对架空线真双极MMC-HVDC系统,分别从交流系统和换流阀的角度分析架空线路单极接地故障的等值电路模型和故障特性,推导故障电流的解析表达式。提出了一种新型故障限流模块,可有效抑制闭锁后短路电流幅值。依靠该限流模块的限流能力,设计了换流站快速重启策略。仿真结果证明,该限流方案可有效限制桥臂电流的大小及上升速率,消除系统交流侧及换流器内部续流二极管的过流危害,减小直流断路器的动作难度,加速故障极换流站重启,减少系统停运时间。展开更多
An InGaAs/InP DHBT with an InGaAsP composite collector is designed and fabricated using triple mesa structural and planarization technology. All processes are on 3-inch wafers. The DHBT with an emitter area of 1×...An InGaAs/InP DHBT with an InGaAsP composite collector is designed and fabricated using triple mesa structural and planarization technology. All processes are on 3-inch wafers. The DHBT with an emitter area of 1×15 μm2 exhibits a current cutoff frequency ft = 170 GHz and a maximum oscillation frequency fmax = 256 GHz. The breakdown voltage is 8.3 V, which is to our knowledge the highest BVcEo ever reported for InGaAs/InP DHBTs in China with comparable high frequency performances. The high speed InGaAs/InP DHBTs with high breakdown voltage are promising for voltage-controlled oscillator and mixer applications at W band or even higher frequencies.展开更多
基金Project supported by the National Natural Science Foundation of China(Grant No.61501091)the Fundamental Research Funds for the Central Universities of Ministry of Education of China(Grant Nos.ZYGX2014J003 and ZYGX2013J020)
文摘Design and characterization of a G-band（140–220 GHz） terahertz monolithic integrated circuit（TMIC） amplifier in eight-stage common-emitter topology are performed based on the 0.5-μm In Ga As/In P double heterojunction bipolar transistor（DHBT）. An inverted microstrip line is implemented to avoid a parasitic mode between the ground plane and the In P substrate. The on-wafer measurement results show that peak gains are 20 dB at 140 GHz and more than 15-dB gain at 140–190 GHz respectively. The saturation output powers are-2.688 dBm at 210 GHz and-2.88 dBm at 220 GHz,respectively. It is the first report on an amplifier operating at the G-band based on 0.5-μm InP DHBT technology. Compared with the hybrid integrated circuit of vacuum electronic devices, the monolithic integrated circuit has the advantage of reliability and consistency. This TMIC demonstrates the feasibility of the 0.5-μm InGaAs/InP DHBT amplifier in G-band frequencies applications.
基金Supported by the National Basic Research Program of China under Grant No 2011CB301900the Natural Science Foundation of Jiangsu Province under Grant Nos BK2011010 and BY2013077
文摘A common base four-finger InOaAs/InP double heterojunction bipolar transistor with 535 OHz fmax by using the 0.5 μm emitter technology is fabricated. Multi-finger design is used to increase the input current. Common base configuration is compared with common emitter configuration, and shows a smaller K factor at high frequency span, indicating a larger breakpoint frequency of maximum stable gain/maximum available gain （MSG/MAG） and thus a higher gain near the cut-off frequency, which is useful in THz amplifier design.
基金Project supported by the National Basic Research Program of China (Grant No. 2010CB327502)
文摘A physical model for scaling and optimizing InGaAs/InP double heterojunction bipolar transistors（DHBTs） based on hydrodynamic simulation is developed.The model is based on the hydrodynamic equation,which can accurately describe non-equilibrium conditions such as quasi-ballistic transport in the thin base and the velocity overshoot effect in the depleted collector.In addition,the model accounts for several physical effects such as bandgap narrowing,variable effective mass,and doping-dependent mobility at high fields.Good agreement between the measured and simulated values of cutoff frequency,f t,and maximum oscillation frequency,f max,are achieved for lateral and vertical device scalings.It is shown that the model in this paper is appropriate for downscaling and designing InGaAs/InP DHBTs.
文摘Background: Although treatment guidelines for bipolar disorder in many countries commonly include lithium carbonate joint with sodium valproate, this combination is not effective for all patients. Moreover, some adverse reactions related to this treatment, neurotoxicity and interaction with other drugs justify and call for a new reviewing of the issue. Methods: Evidence base for the interactions of combined drugs, the metabolic features, action mechanism, efficacy and side effects of these treatment combinations were reviewed. Considerable attention was given to the relationship of the mutual action of these drugs with their clinical efficacy but also their side effects. Results: The efficacy of combination therapy of lithium with valproate for treatment and prevention of mania were superior to monotherapy of lithium or valproate. Conclusion: Double mood stabilizer therapy is the best relative treatment for patients with bipolar disorder, especially mania and related episodes.
文摘基于模块化多电平换流器的高压柔性直流输电系统(modular multilevel converter-based high voltage direct current,MMC-HVDC)常采用双极接线方式以提高系统功率输送能力和可靠性。然而目前对于风电场经柔直外送系统的稳定性研究集中于单极接线方式,孤岛直驱风电场与采用不同双极协调控制的双极MMC-HVDC互联系统小信号稳定性问题还有待进一步探究。该文首先考虑频率耦合特性、参考系初相位和直流侧耦合特性的影响,分别建立了采用双U/f下垂控制和定U/f-P/Q控制的双极MMC-HVDC系统交流侧等效SISO阻抗模型,并详细分析了金属回线阻抗和双极间功率均分度对交流阻抗特性的影响。接着对比研究了两种协调控制中共有控制环路和特有控制环路对交流侧负电阻特性及互联系统稳定性的影响规律。最后,孤岛直驱风电场经两种双极协调控制下双极MMC-HVDC外送系统Matlab/Simulink时域仿真结果和硬件在环半实物实时仿真实验结果验证了所提出的小信号阻抗模型的精确性和稳定性分析结论的有效性。
基金supported by the National Natural Science Foundation of China (Grant No. 51277146)the Foundation of Delta Science,Technologythe Education Development Program for Power Electronics (Grant No. DREG2011003)
文摘By deriving the discrete-time models of a digitally controlled H-bridge inverter system modulated by bipolar sinu- soidal pulse width modulation （BSPWM） and unipolar double-frequency sinusoidal pulse width modulation （UDFSPWM） respectively, the performances of the two modulation strategies are analyzed in detail. The circuit parameters, used in this paper, are fixed. When the systems, modulated by BSPWM and UDFSPWM, have the same switching frequency, the stabil- ity boundaries of the two systems are the same. However, when the equivalent switching frequencies of the two systems are the same, the BSPWM modulated system is more stable than the UDFSPWM modulated system. In addition, a convenient method of establishing the discrete-time model of piecewise smooth system is presented. Finally, the analytical results are confirmed by circuit simulations and experimental measurements.
文摘二极管中点钳位NPC(neutral point clamped)三电平逆变器具备较低的开关应力、谐波分量和较好的抗干扰能力,促使其成为光伏、储能等新能源领域DC-AC变换器的主要拓扑之一。针对大功率应用场景中普遍采用的NPC三电平IGBT功率半导体模块开展研究,分析NPC三电平功率模块的换流回路,并据此给出对应换流回路的寄生参数精准仿真评估方法。依据换流回路寄生参数最小原则,设计适用于NPC三电平功率半导体模块的动态特性测试电路。根据换流回路以及电路工作原理,设计NPC三电平功率模块的驱动电路,并给出增强驱动电流、防直通及死区时间可调的驱动方案。最后,通过对NPC三电平IGBT模块的动态测试,详细评估了不同工况下功率器件的动态损耗。
文摘随着模块化多电平换流器直流输电(modular multilevel converter based HVDC,MMC-HVDC)的快速发展,远距离大容量架空线直流输电系统随之出现。相比于电缆线路,架空线输电易发生短路、闪络等瞬时故障,必须采取相应措施限制故障电流,避免系统停运。针对架空线真双极MMC-HVDC系统,分别从交流系统和换流阀的角度分析架空线路单极接地故障的等值电路模型和故障特性,推导故障电流的解析表达式。提出了一种新型故障限流模块,可有效抑制闭锁后短路电流幅值。依靠该限流模块的限流能力,设计了换流站快速重启策略。仿真结果证明,该限流方案可有效限制桥臂电流的大小及上升速率,消除系统交流侧及换流器内部续流二极管的过流危害,减小直流断路器的动作难度,加速故障极换流站重启,减少系统停运时间。
文摘An InGaAs/InP DHBT with an InGaAsP composite collector is designed and fabricated using triple mesa structural and planarization technology. All processes are on 3-inch wafers. The DHBT with an emitter area of 1×15 μm2 exhibits a current cutoff frequency ft = 170 GHz and a maximum oscillation frequency fmax = 256 GHz. The breakdown voltage is 8.3 V, which is to our knowledge the highest BVcEo ever reported for InGaAs/InP DHBTs in China with comparable high frequency performances. The high speed InGaAs/InP DHBTs with high breakdown voltage are promising for voltage-controlled oscillator and mixer applications at W band or even higher frequencies.
