1,721,041 research outputs found
Noise in Almost Ideal n+-p Junctions
No full textNoise measurements performed on almost-ideal n+-p junctions in the frequency range 0.1Hz-10kHz show that shot noise extends down to a corner frequency f* much lower than in most commercial junction diodes. Such results agree with theories that ascribe the 1/f noise to the device defect centers, and to the dispersion in their properties
Real-Time AMPC for Loss Reduction in 48 V Six-Phase Synchronous Motor Drives
No full textThis article presents an adaptive model predictive control (AMPC) algorithm for real-time management of a six-phase permanent magnet synchronous motor. The system optimizes both speed control and power dissipation, featuring an automated power derating mechanism for overload conditions. AMPC demonstrated advantages over traditional field-oriented control, including reduced losses and lower energy consumption, while maintaining robust performance and high speed control precision. Validation through hardware-in-the-loop testing on the dSPACE platform confirmed its effectiveness. The contribution focuses on enhanced stability, robustness, and integrating predictive features to further improve efficiency and adaptability in electric drive systems. © 2025 The Author(s). IET Power Electronics published by John Wiley & Sons Ltd on behalf of The Institution of Engineering and Technology
Techniques for high-sensitivity measurements of shot noise in nanostructures
No full textRecent theoretical and experimental findings have raised interest in the issue
of shot noise suppression and enhancement in nanostructures. Several
theoretical predictions have already been confirmed by means of sophisticated
experiments, but further work is needed to improve the achievable sensitivity
of noise measurements.
We have been working on the integration of several different noise reduction
techniques, with the objective of being able to measure the shot noise levels
associated with currents of less than a picoampere. We combine the
usage of correlation amplifiers, cryogenic cooling of the active elements
and feedback resistors, correction techniques based on the substitution
impedance method, and the precise evaluation of the transfer function of the
amplifiers
Photocurrent transients in almost ideal silicon p-n junctions
No full textResults obtained from measurements and spectroscopic analysis of current transients induced in almost ideal silicon n(+) - p junctions by infra-red stimulation n illuminating a reverse biased junction by means of an infra-red emitting diode for a few seconds, a current transient is generated which, at 0 degrees C, lasts several hours. This can be decomposed, by means of a proper spectroscopic method, into a sum of four exponential contributions with time constants ranging from tens up to thousands of seconds. Similar dark current transients were already obtained for the same junctions when they were stimulated by a change of the reverse bias voltage, without any optical excitation. The spectroscopy of both optical and voltage induced current transients gives four exponential components with the same time constants. Both the dark current and the photocurrent transients are ascribed to the same SiyOx clusters containing hundreds of Si atoms and four types of single energy level defect centers with different localization. While the voltage induced current transients implicate the activation of such defect centers in the p-region near the n(+) - p interface only, those due to the photostimulation produce their activation throughout the whole n(+) region as well. This fact leads to much greater values for the transient photocurrent in n comparison to those induced by voltage changes and, as a consequence, to greater reliability and accuracy in the measurements and in the results obtained from their analysis. (C) 1995 American Institute of Physics
2010 14th International Workshop on Computational Electronics
No full textThe proceedings contain 87 papers. The topics discussed include: band structure and ballistic conductance of strained Si nanowires; point defect scattering in silicon nanowires; high-order spherical harmonics solution of the Boltzmann equation and noise modeling; a percolative approach to transport and excess noise in polyacene semiconductors; a deterministic Boltzmann solver for GaAs devices based on the spherical harmonics expansion; a Monte Carlo simulation of reproducible hysteresis in RRAM; quantum transport of Dirac fermions in graphene nanostructures; phonon and electron transport in graphene nanoribbons; numerical solution of the Dirac equation for an armchair graphene nanoribbon in the presence of a transversally variable potential; model-comparison study of quasi-ballistic electron transport in nanoscale semiconductor devices; and a reduced-order technique for the acceleration of electronic structure calculations
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