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Full-Text Articles in Engineering
Losses In Electric Power Systems, E. Benedict, T. Collins, D. Gotham, S. Hoffman, D. Karipides, S. Pekarek, R. Ramabhadran
Losses In Electric Power Systems, E. Benedict, T. Collins, D. Gotham, S. Hoffman, D. Karipides, S. Pekarek, R. Ramabhadran
Department of Electrical and Computer Engineering Technical Reports
This report concerns losses in power systems. The report was assembled by seven authors in EE 532 class at Purdue University in December, 1992. The work was part of a class project on losses . All aspects of losses are discussed from the transmission system through utilization stages. High efficiency motors and lighting are also considered . The students participating in this project also videotaped presentations on power system losses .
Implementation Of Back-Propagation Neural Networks With Matlab, Jamshid Nazari, Okan K. Ersoy
Implementation Of Back-Propagation Neural Networks With Matlab, Jamshid Nazari, Okan K. Ersoy
Department of Electrical and Computer Engineering Technical Reports
The artificial neural network back propagation algorithm is implemented in Matlab language. This implementation is compared with several other software packages. The effect of reducing the number of iterations in the performance of the algorithm iai studied. The speed of the back propagation program, mkckpmp, written in Matlab language is compared with the speed of several other back propagation programs which are written in the C language. The speed of the Matlab program mbackpmp is, also compared with the C program quickpmp which is a variant of the back propagation algorithm. It is shown that the Matlab program mbackpmp is …
A Study Of Numerical Integration Techniques For Use In The Companion Circult Method Of Transient Circuit Analysis, Charles A. Thompson
A Study Of Numerical Integration Techniques For Use In The Companion Circult Method Of Transient Circuit Analysis, Charles A. Thompson
Department of Electrical and Computer Engineering Technical Reports
Circuit transient analysis packages such as SPICE and EMTP are very widely used, but detailed information on the internal structure and error characteristics for these software packages is lacking. Both SPICE and EMTP rely on numerical integration to approximate the transient response of circuit elements. The numerical integration methods used in the packages are not necessarily the most accurate approximations to the actual response of a circuit. The study of these numerical integration methods and their error characteristics is the focus of this thesis. Comparisons are made between several methods in terms of accuracy and stability as well as algorithm …
Three-Dimensional Insulated Gate Bipolar Transistor (Igbt) Development, P.V. Gilbert, G.W. Neudeck
Three-Dimensional Insulated Gate Bipolar Transistor (Igbt) Development, P.V. Gilbert, G.W. Neudeck
Department of Electrical and Computer Engineering Technical Reports
A new insulated gate bipolar transistor structure, the 3D-IGBT, is presented. The 3D-IGBT utilizes selective epitaxial silicon to form a top contacted anode and still retain the cellular structure of vemcally oriented devices. The 3D-IGBT , unlike other fully integrable power devices, exploits the merits of cellular structure to increase its packing density and thus reduce its on-resistance per unit area. It also eliminates the parasitic JFET resistance found in vertical IGBT's. To integrate the 3D-IGBT with low power devices, the QDI method of device isolation is also presented. QDI uses a combination of JI and DI to electrically isolate …
Minority Hole Mobility In N+ Gaas, Michael L. Lovejoy, Michael R. Melloch, Mark S. Lundstrom, R. K. Ahrenkiel
Minority Hole Mobility In N+ Gaas, Michael L. Lovejoy, Michael R. Melloch, Mark S. Lundstrom, R. K. Ahrenkiel
Department of Electrical and Computer Engineering Faculty Publications
The minority hole diffusivity, or equivalently the hole mobility, was measured in n+GaAs with the zero‐field time‐of‐flight technique. The minority hole mobility was measured for the donor doping range of 1.3×1017 cm−3 to 1.8×1018 cm−3 and was found to vary from 235 to 295 cm2/V s. At the lower doping level, the minority hole mobility is comparable to the corresponding majority hole mobility, but at 1.8×1018 cm−3 the minority hole mobility was 30% higher than the majority carrier hole mobility. These results have important implications for the design of devices such …
Self‐Consistent Scattering Matrix Calculation Of The Distribution Function In Semiconductor Devices, Mark A. Stettler, Mark S. Lundstrom
Self‐Consistent Scattering Matrix Calculation Of The Distribution Function In Semiconductor Devices, Mark A. Stettler, Mark S. Lundstrom
Department of Electrical and Computer Engineering Faculty Publications
The scattering matrix approach is a new technique for solving the Boltzmann equation in devices. We report a self-consistent application of the technique to realistic silicon devices exhibiting strong nonlocal effects. Simulation of a hot-electron, n-i-n diode demonstrates that the new technique efficiently and accurately reproduces Monte Carlo results without the statistical noise, allowing much tighter convergence with Poisson’s equation.
Microsecond Lifetimes And Low Interface Recombination Velocities In Moderately Doped N-Gaas Thin Films, Gregory Benedict Lush, D. H. Levi, H. F. Macmillan, Michael R. Melloch, Mark S. Lundstrom, R. K. Ahrenkiel
Microsecond Lifetimes And Low Interface Recombination Velocities In Moderately Doped N-Gaas Thin Films, Gregory Benedict Lush, D. H. Levi, H. F. Macmillan, Michael R. Melloch, Mark S. Lundstrom, R. K. Ahrenkiel
Department of Electrical and Computer Engineering Faculty Publications
We have observed lifetimes greater than 1 ps in moderately doped, thin film, n-GaAs/A1a,Gae,As double heterostructure membranes formed by etching away the substrate. We attribute these ultralong lifetimes to enhanced photon recycling caused by the removal of the substrate. Nonradiative recombination in the bulk and at the interfaces is very low; the upper limit of the interface recombination velocity is 25 cm/S.-Such long lifetimes in GaAs doped at N,= 1.3 X 10” cme3 suggest that thin-film solar cells offer a potential option for achieving very high efficiencies.
Comparative Study Of Minority Electron Properties In P+-Gaas Doped With Beryllium And Carbon, Michael L. Lovejoy, Michael R. Melloch, Mark S. Lundstrom, R. K. Ahrenkiel, B. M. Keyes, T. J. De Lyon, J. M. Woodall
Comparative Study Of Minority Electron Properties In P+-Gaas Doped With Beryllium And Carbon, Michael L. Lovejoy, Michael R. Melloch, Mark S. Lundstrom, R. K. Ahrenkiel, B. M. Keyes, T. J. De Lyon, J. M. Woodall
Department of Electrical and Computer Engineering Faculty Publications
Minority electron properties in p+‐GaAs doped with beryllium (Be) and with carbon (C) are reported. Measurements of essentially identical responses for structures differing only in dopant element demonstrate that the diffusivity (Dn) and the diffusion lengths (Ln) are the same in p+‐GaAs doped to ∼1019 cm−3 with Be‐ and C‐dopants. Zero‐field time‐of‐flight analysis yields Dn=35 cm2/s and internal quantum efficiency analysis yields Ln=2.4 μm, which implies a lifetime that is approximately at the estimated radiative limit. In addition, the majority Hall mobility was also found to be identical …
A Study Of Minority Carrier Lifetime Versus Doping Concentration In N‐Type Gaas Grown By Metalorganic Chemical Vapor Deposition, Gregory Benedict Lush, H. F. Macmillan, B. M. Keyes, D. H. Levi, Michael R. Melloch, R. K. Ahrenkiel, Mark S. Lundstrom
A Study Of Minority Carrier Lifetime Versus Doping Concentration In N‐Type Gaas Grown By Metalorganic Chemical Vapor Deposition, Gregory Benedict Lush, H. F. Macmillan, B. M. Keyes, D. H. Levi, Michael R. Melloch, R. K. Ahrenkiel, Mark S. Lundstrom
Department of Electrical and Computer Engineering Faculty Publications
Time‐resolved photoluminescence decay measurements are used to explore minority carrier recombination in n‐type GaAs grown by metalorganic chemical vapor deposition, and doped with selenium to produce electron concentrations from 1.3×1017 cm−3 to 3.8×1018 cm−3. For electron densities n0<1018 cm−3, the lifetime is found to be controlled by radiative recombination and photon recycling with no evidence of Shockley–Read–Hall recombination. For higher electron densities, samples show evidence of Shockley–Read–Hall recombination as reflected in the intensity dependence of the photoluminescence decay. Still, we find that radiative recombination and photon recycling are important for …
Minority Electron Transport In Inp/Ingaas Heterojunction Bipolar Transistors, Paul Dodd, Mark S. Lundstrom
Minority Electron Transport In Inp/Ingaas Heterojunction Bipolar Transistors, Paul Dodd, Mark S. Lundstrom
Department of Electrical and Computer Engineering Faculty Publications
Electron transport across the base of InP/InGaAs heterojunction bipolar transistors is examined by Monte Carlo simulation. The base transit times and electron distribution functions are examined as a function of basewidth. Clear ballistic behavior is observed only for extremely thin bases (much less than 100 A). Over the range of basewidths of interest for devices, base transport appears diffusive, but the electrons are very far from thermal equilibrium. The diffusive behavior is shown to arise from the sensitivity of the steady-state carrier population to small amounts of large-angle scattering.