We present novel Schottky barrier field effect transistors consisting of a parallel array of bottom-up grown silicon nanowires that are able to deliver high current outputs. Axial silicidation of the nanowires is used...We present novel Schottky barrier field effect transistors consisting of a parallel array of bottom-up grown silicon nanowires that are able to deliver high current outputs. Axial silicidation of the nanowires is used to create defined Schottky junctions leading to on/off current ratios of up to 106. The device concept leverages the unique transport properties of nanoscale junctions to boost device performance for macroscopic applications. Using parallel arrays, on-currents of over 500 gA at a source-drain voltage of 0.5 V can be achieved. The transconductance is thus increased significantly while maintaining the transfer characteristics of single nanowire devices. By incorporating several hundred nanowires into the parallel arra36 the yield of functioning transistors is dramatically increased and device- to-device variability is reduced compared to single devices. This new nanowire- based platform provides sufficient current output to be employed as a transducer for biosensors or a driving stage for organic light-emitting diodes （LEDs）, while the bottom-up nature of the fabrication procedure means it can provide building blocks for novel printable electronic devices.展开更多
An ultra-low quiescent current low-dropout regulator with small output voltage variations and improved load regulation is presented in this paper. It makes use of dynamically-biased shunt feedback as the buffer stage ...An ultra-low quiescent current low-dropout regulator with small output voltage variations and improved load regulation is presented in this paper. It makes use of dynamically-biased shunt feedback as the buffer stage and the LDO regulator can be stable for all load conditions. The proposed structure also employs a momentarily current-boosting circuit to reduce the output voltage to the normal value when output is switched from full load to no load. The whole circuit is designed in a 0.18 μm CMOS technology with a quiescent current of 550 nA. The maximum output voltage variation is less than 20 mV when used with 1 μF external capacitor.展开更多
We report on the room-temperature cascade laser （QCL） at λ -4.7μm. cw operation of a surface grating Both grating design and material distributed feedback （DFB） quantum optimization are used to decrease the thre...We report on the room-temperature cascade laser （QCL） at λ -4.7μm. cw operation of a surface grating Both grating design and material distributed feedback （DFB） quantum optimization are used to decrease the threshold current density and to increase the output power. For a high-reflectivity-coated 13-μm-wide and 4- mm-long laser, high wall-plug efficiency of 6% is obtained at 20℃ from a single facet producing over I W of ew output power. The threshold current density of DFB QCL is as low as 1.13kA/cm^2 at 10℃ and 1.34kA/cm2 at 30℃ in cw mode. Stable single-mode emission with a side-mode suppression ratio of about 30 dB is observed in tile working temperature range of 20-50℃.展开更多
为使对换流阀工作状态的控制更加精确、抑制换相失败,提出了一种基于多分支多输入多输出(Multiple input multiple output,MIMO)深度学习的高压直流输电(Line commutated converter high voltage direct current,LCC-HVDC)换流器阀电流...为使对换流阀工作状态的控制更加精确、抑制换相失败,提出了一种基于多分支多输入多输出(Multiple input multiple output,MIMO)深度学习的高压直流输电(Line commutated converter high voltage direct current,LCC-HVDC)换流器阀电流波形反演方案。对现行实际工程中常用的基于差流换相失败的检测方案进行仿真分析,发现检测结果存在滞后性。阀电流波形的反演模型,其输入特征量为三相交流电流、输出量为6个阀电流,属于MIMO的场景。为提取更多特征信息,基于Inception-ResNet结构、采用多种不同尺寸的卷积,设计多分支MIMO深度学习的换流器阀电流反演模型,并以三相电流作为模型输入,6个阀电流作为输出量,对多分支MIMO模型进行训练。最后,对阀电流的波形进行预测反演。仿真结果表明,多分支MIMO模型对阀电流波形的反演具有较好的适用性,反演结果的相关系数在0.9836以上、平均绝对误差在0.1284以下、且均方误差在0.0286以内,误差变化程度较低。展开更多
Abstract---The stability of the drive current is very important for a laser driver, while it is difficult to maintain the current stable at a high value for the laser driver. On the other hand, the range of the drive ...Abstract---The stability of the drive current is very important for a laser driver, while it is difficult to maintain the current stable at a high value for the laser driver. On the other hand, the range of the drive current is expected to be as wide as possible to be applied to different kinds of lasers. In this paper, a high current laser driver for the superluminescent light emitting diode （SLED） is presented, which is used in the optic fiber gyro embedded by a 0.35 μm bipolar complementary metal-oxide-semiconductor transistor （BiCMOS） process. The laser driver provides automatic power control and certain value of current determined by the external resister. The system is based on the optic-electric feedback theory and uses the closed-loop control technique to maintain the drive current stable. The system is capable of producing stable current ranges from 4 mA to 200 mA when the value of external resister changes.展开更多
文摘We present novel Schottky barrier field effect transistors consisting of a parallel array of bottom-up grown silicon nanowires that are able to deliver high current outputs. Axial silicidation of the nanowires is used to create defined Schottky junctions leading to on/off current ratios of up to 106. The device concept leverages the unique transport properties of nanoscale junctions to boost device performance for macroscopic applications. Using parallel arrays, on-currents of over 500 gA at a source-drain voltage of 0.5 V can be achieved. The transconductance is thus increased significantly while maintaining the transfer characteristics of single nanowire devices. By incorporating several hundred nanowires into the parallel arra36 the yield of functioning transistors is dramatically increased and device- to-device variability is reduced compared to single devices. This new nanowire- based platform provides sufficient current output to be employed as a transducer for biosensors or a driving stage for organic light-emitting diodes （LEDs）, while the bottom-up nature of the fabrication procedure means it can provide building blocks for novel printable electronic devices.
文摘An ultra-low quiescent current low-dropout regulator with small output voltage variations and improved load regulation is presented in this paper. It makes use of dynamically-biased shunt feedback as the buffer stage and the LDO regulator can be stable for all load conditions. The proposed structure also employs a momentarily current-boosting circuit to reduce the output voltage to the normal value when output is switched from full load to no load. The whole circuit is designed in a 0.18 μm CMOS technology with a quiescent current of 550 nA. The maximum output voltage variation is less than 20 mV when used with 1 μF external capacitor.
基金Supported by the National Basic Research Program of China under Grant Nos 2013CB632801 and 2013CB632803the National Natural Science Foundation of China under Grant Nos 61435014,61306058 and 61274094the Beijing Natural Science Foundation under Grant No 4144086
文摘We report on the room-temperature cascade laser （QCL） at λ -4.7μm. cw operation of a surface grating Both grating design and material distributed feedback （DFB） quantum optimization are used to decrease the threshold current density and to increase the output power. For a high-reflectivity-coated 13-μm-wide and 4- mm-long laser, high wall-plug efficiency of 6% is obtained at 20℃ from a single facet producing over I W of ew output power. The threshold current density of DFB QCL is as low as 1.13kA/cm^2 at 10℃ and 1.34kA/cm2 at 30℃ in cw mode. Stable single-mode emission with a side-mode suppression ratio of about 30 dB is observed in tile working temperature range of 20-50℃.
文摘为使对换流阀工作状态的控制更加精确、抑制换相失败,提出了一种基于多分支多输入多输出(Multiple input multiple output,MIMO)深度学习的高压直流输电(Line commutated converter high voltage direct current,LCC-HVDC)换流器阀电流波形反演方案。对现行实际工程中常用的基于差流换相失败的检测方案进行仿真分析,发现检测结果存在滞后性。阀电流波形的反演模型,其输入特征量为三相交流电流、输出量为6个阀电流,属于MIMO的场景。为提取更多特征信息,基于Inception-ResNet结构、采用多种不同尺寸的卷积,设计多分支MIMO深度学习的换流器阀电流反演模型,并以三相电流作为模型输入,6个阀电流作为输出量,对多分支MIMO模型进行训练。最后,对阀电流的波形进行预测反演。仿真结果表明,多分支MIMO模型对阀电流波形的反演具有较好的适用性,反演结果的相关系数在0.9836以上、平均绝对误差在0.1284以下、且均方误差在0.0286以内,误差变化程度较低。
文摘Abstract---The stability of the drive current is very important for a laser driver, while it is difficult to maintain the current stable at a high value for the laser driver. On the other hand, the range of the drive current is expected to be as wide as possible to be applied to different kinds of lasers. In this paper, a high current laser driver for the superluminescent light emitting diode （SLED） is presented, which is used in the optic fiber gyro embedded by a 0.35 μm bipolar complementary metal-oxide-semiconductor transistor （BiCMOS） process. The laser driver provides automatic power control and certain value of current determined by the external resister. The system is based on the optic-electric feedback theory and uses the closed-loop control technique to maintain the drive current stable. The system is capable of producing stable current ranges from 4 mA to 200 mA when the value of external resister changes.
