The Experts below are selected from a list of 123 Experts worldwide ranked by ideXlab platform
Masahito Shoyama - One of the best experts on this subject based on the ideXlab platform.
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A Unified Dynamic Model for Bi-directional DC-DC Converter
2014Co-Authors: Husam A. Ramadan, Yasutaka Imamura, Sihun Yang, Masahito ShoyamaAbstract:This paper presents a unified model for bi-directional DC-DC converters for both directions of power flow. The bi-directional DC-DC converter is analyzed using a seamless dynamic model with an Independent Voltage Source and an Independent current Source, which polarity depends on the direction of the power flow. A small signal model is derived using a state space averaging method. Furthermore, the transient response and the frequency characteristics are discussed. Example circuits for bi-directional DC-DC converter are investigated analytically, using simulation, and experimentally.
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Seamless dynamic model for bi-directional DC-DC converter
2013 IEEE 10th International Conference on Power Electronics and Drive Systems (PEDS), 2013Co-Authors: Yasutaka Imamura, Husam A. Ramadan, Sihun Yang, Gamal M. Dousoky, Masahito ShoyamaAbstract:In this paper, bi-directional DC-DC converter is analyzed using a seamless dynamic model with an Independent Voltage Source and an Independent current Source, which polarity depends on the direction of the power flow. In the seamless dynamic model, the Independent Voltage Source represents a battery and an Independent current Source represents the load or energy Source. A small signal model is derived using a state space averaging method, and simulated results about the transient response characteristics are presented.
W.s. Lour - One of the best experts on this subject based on the ideXlab platform.
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The influence of base bias on the collector photocurrent for InGaP∕GaAs heterojunction phototransistors
Journal of Applied Physics, 2005Co-Authors: H.r. Chen, W.t. Chen, W.s. LourAbstract:Fabrication, characterization, and theoretical modeling of two-terminal and three-terminal heterojunction phototransistors ( 2T- and 3T-HPTs) based on InGaP∕GaAs are reported. For a current–bias 3T-HPT, an Independent current flowing into or out of base electrode is employed to modulate the operating point of a heterojunction bipolar transistor (HBT). The operating point of a HBT in the presence of a positive bias current can be tuned to a higher current level where the current gain is larger. It is found that the optical gain increases from 28.4 for a 2T-HPT to 34 for a 3T-HPT with a bias current of 10μA. The achievement of tunability of the operating point of a HBT has also been attempted with an Independent Voltage Source. Nevertheless, our work reveals that the p–i–n photocurrent generated within the B–C region contributes very little to the final collector photocurrent for a Voltage–bias 3T-HPT, resulting in a rather small optical gain in the range 0.8–1.6. A simple equivalent circuit model is develo...
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A new model for the phototransistor
The Fourth International Workshop on Junction Technology 2004. IWJT '04., 2004Co-Authors: W.t. Chen, W.s. LourAbstract:We reported the fabrication, characterization and modeling of a heterojunction phototransistor. Both Gummel-plot and common-emitter configurations are employed to characterize HPT's performances and to clearly demonstrate what difference between a Voltage-biased and a current-biased HPT. The performances of the Voltage- and current-Source biased HPTs were also compared to the results from a newly proposed HPT model and related circuit with good agreement found. Although an Independent Voltage Source pushes HBT's operating point to a higher current level. where the dc current gain is larger, however, the photocurrent generated within B-C region gives very little contribution to final collector current. The optical gain obtained from high-Voltage-Source biased HPT is even smaller than that of a HPT with a floating base. In addition, a modified extended Ebers-Moll model was successfully used to analyze what the common-emitter characteristics and Gummel-plot differences with input base current as well as base-en-Litter Voltage between the dark and illumination situation.
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The Effect on Base Bias for InGaP/GaAs Heterojunction Phototransistors
Conference on Optoelectronic and Microelectronic Materials and Devices 2004., 2004Co-Authors: H.r. Chen, W.t. Chen, W.s. LourAbstract:We reported on characterization of 2-terminal and 3-terminal InGaP/GaAs heterojunction phototransistors (HPTs). For a current-bias 3T-HPT, an Independent current flowing into or out of base electrode is employed. Addition of biased current pushes HBT's operating point to a higher current level where the current gain is larger. It is found that the optical gain increases from 28.4 for a 2T-HPT to 34 for a 3T-HPT with a biased current of 10 μA. Although an Independent Voltage Source also pushes HBT's operating point to a higher current level, p-i-n photocurrent generated within the B-C region contributes very few to final collector photocurrent for a Voltage-bias 3T-HPT. The optical gain obtained from Voltage-bias 3T-HPT is as small as 0.8 ∼ 1.6
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Characteristics and modeling of heterojunction phototransistor with DC base bias
2004Co-Authors: H.r. Chen, W.t. Chen, W.s. LourAbstract:In this paper, we reported the fabrication, characterization and modeling of a heterojunction phototransistor. The Gummel-plot configuration is employed to characterize HPT's performances and to clearly demonstrate the Voltage HPT. The performances of the Voltagee biased HPTs were also compared to the results from a newly proposed HPT model and related circuit with good agreement found. Although an Independent Voltage Source pushes HBT's operating point to a higher current level where the dc current gain is larger, however, the photocurrent generated within B-C region gives very little contribution to final collector current. In addition, a modified extended Ebers-Moll model was successfully used to analyze what the common-emitter characteristics and Gummel-plot differences with input base current as well as base-emitter Voltage between the dark and illumination situation.
Husam A. Ramadan - One of the best experts on this subject based on the ideXlab platform.
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A Unified Dynamic Model for Bi-directional DC-DC Converter
2014Co-Authors: Husam A. Ramadan, Yasutaka Imamura, Sihun Yang, Masahito ShoyamaAbstract:This paper presents a unified model for bi-directional DC-DC converters for both directions of power flow. The bi-directional DC-DC converter is analyzed using a seamless dynamic model with an Independent Voltage Source and an Independent current Source, which polarity depends on the direction of the power flow. A small signal model is derived using a state space averaging method. Furthermore, the transient response and the frequency characteristics are discussed. Example circuits for bi-directional DC-DC converter are investigated analytically, using simulation, and experimentally.
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Seamless dynamic model for bi-directional DC-DC converter
2013 IEEE 10th International Conference on Power Electronics and Drive Systems (PEDS), 2013Co-Authors: Yasutaka Imamura, Husam A. Ramadan, Sihun Yang, Gamal M. Dousoky, Masahito ShoyamaAbstract:In this paper, bi-directional DC-DC converter is analyzed using a seamless dynamic model with an Independent Voltage Source and an Independent current Source, which polarity depends on the direction of the power flow. In the seamless dynamic model, the Independent Voltage Source represents a battery and an Independent current Source represents the load or energy Source. A small signal model is derived using a state space averaging method, and simulated results about the transient response characteristics are presented.
Yasutaka Imamura - One of the best experts on this subject based on the ideXlab platform.
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A Unified Dynamic Model for Bi-directional DC-DC Converter
2014Co-Authors: Husam A. Ramadan, Yasutaka Imamura, Sihun Yang, Masahito ShoyamaAbstract:This paper presents a unified model for bi-directional DC-DC converters for both directions of power flow. The bi-directional DC-DC converter is analyzed using a seamless dynamic model with an Independent Voltage Source and an Independent current Source, which polarity depends on the direction of the power flow. A small signal model is derived using a state space averaging method. Furthermore, the transient response and the frequency characteristics are discussed. Example circuits for bi-directional DC-DC converter are investigated analytically, using simulation, and experimentally.
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Seamless dynamic model for bi-directional DC-DC converter
2013 IEEE 10th International Conference on Power Electronics and Drive Systems (PEDS), 2013Co-Authors: Yasutaka Imamura, Husam A. Ramadan, Sihun Yang, Gamal M. Dousoky, Masahito ShoyamaAbstract:In this paper, bi-directional DC-DC converter is analyzed using a seamless dynamic model with an Independent Voltage Source and an Independent current Source, which polarity depends on the direction of the power flow. In the seamless dynamic model, the Independent Voltage Source represents a battery and an Independent current Source represents the load or energy Source. A small signal model is derived using a state space averaging method, and simulated results about the transient response characteristics are presented.
Sihun Yang - One of the best experts on this subject based on the ideXlab platform.
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A Unified Dynamic Model for Bi-directional DC-DC Converter
2014Co-Authors: Husam A. Ramadan, Yasutaka Imamura, Sihun Yang, Masahito ShoyamaAbstract:This paper presents a unified model for bi-directional DC-DC converters for both directions of power flow. The bi-directional DC-DC converter is analyzed using a seamless dynamic model with an Independent Voltage Source and an Independent current Source, which polarity depends on the direction of the power flow. A small signal model is derived using a state space averaging method. Furthermore, the transient response and the frequency characteristics are discussed. Example circuits for bi-directional DC-DC converter are investigated analytically, using simulation, and experimentally.
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Seamless dynamic model for bi-directional DC-DC converter
2013 IEEE 10th International Conference on Power Electronics and Drive Systems (PEDS), 2013Co-Authors: Yasutaka Imamura, Husam A. Ramadan, Sihun Yang, Gamal M. Dousoky, Masahito ShoyamaAbstract:In this paper, bi-directional DC-DC converter is analyzed using a seamless dynamic model with an Independent Voltage Source and an Independent current Source, which polarity depends on the direction of the power flow. In the seamless dynamic model, the Independent Voltage Source represents a battery and an Independent current Source represents the load or energy Source. A small signal model is derived using a state space averaging method, and simulated results about the transient response characteristics are presented.
