Publications associées à Printed transition for SIW horn antennas - Analytical model

Tower-foot grounding model for EMT programs based on transmission line theory and Marti's model

This paper proposes a tower-foot grounding system model compatible with EMT programs which might be useful for the simulation of lightning transients in overhead lines. The proposed model is based on the solution of the telegrapher's equations and the appl ...

Elsevier2023

Influence of a lossy ground on the lightning performance of overhead transmission lines

Farhad Rachidi-Haeri, Rafael Silva Alipio

This paper investigates the impact of incorporating both displacement currents and frequency-dependent soil parameters in the calculation of the ground-return impedance for the determination of the backflashover rate of 138 kV and 230 kV overhead transmiss ...

Elsevier2023

Semiconductor-based device architectures in multimaterial fibers

William Nicolas Duncan Esposito

Semiconductor materials have given rise to today's digital technology and consumer electronics. Widespread adoption is closely linked to the ability to process and integrate them in devices at scale. Where flexibility and large surfaces are required, such ...

EPFL2023

Potential-induced degradation in bifacial silicon heterojunction solar modules: Insights and mitigation strategies

Christophe Ballif, Quentin Thomas Jeangros, Alessandro Francesco Aldo Virtuani, Luca Gnocchi, Olatz Arriaga Arruti

Potential-induced degradation (PID) may be a serious concern in photovoltaic (PV) modules and plants, particularly when approaching high system voltages (1500+ V). Here, we investigate PID occurring in bifacial rear-emitter silicon heterojunction (SHJ) sol ...

Wiley2023

Accounting for Optical Generation in the Quasi-Neutral Regions of Perovskite Solar Cells

Jean-Michel Sallese, Farzan Jazaeri, Michael Saliba, Parnian Ferdowsi

Predicting the performance of solar cells though analytical models is important for the theory-guided optimization of these devices. Earlier models neglect the impact of the optical generation in the quasi-neutral regions of a perovskite solar cell. Here, ...

IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC2022

Lightning-Induced Voltages on Overhead Distribution Lines Computed through Analytical Expressions for the Electromagnetic Fields

Farhad Rachidi-Haeri, Marcos Rubinstein

The evaluation of lightning ElectroMagnetic (EM) fields represents the most cumbersome part of the lightning-induced voltages computation process. Their evaluation is usually performed through a numerical routine or with simplified analytical expressions, ...

2021

Fabrication of Single-Crystalline InSb-on-Insulator by Rapid Melt Growth

Anna Fontcuberta i Morral, Nicholas Paul Morgan, Heera Menon

InSb has the smallest bandgap and highest electron mobility among III-V semiconductors and is widely used for photodetectors and high-frequency electronic applications. Integration of InSb directly on Si would drastically reduce the fabrication cost and en ...

Wiley2021

Analytical Expressions for Lightning Electromagnetic Fields With Arbitrary Channel-Base Current—Part I: Theory

Marcos Rubinstein

The article provides analytical expressions for the electromagnetic fields generated by a lightning return stroke characterized by a channel-base current with arbitrary time waveform, in presence of either a perfectly conducting or a lossy ground, assuming ...

2021

Ultrafast laser interaction with transparent multi-layer SiO2/Si3N4 films

Yves Bellouard, Ruben Ricca, Victor Carle Adrien Boureau

We investigate the use of ultrafast lasers exposure to induce localized crystallization and elemental redistribution in amorphous dielectric multi-layers, composed of alternating Si3N4 and SiO2 layers of sub-micrometer thickness. Specifically, we report on ...

2021

The Upper Bound of the Speed of Propagation of Waves along a Transmission Line

Farhad Rachidi-Haeri, Marcos Rubinstein

According to theory, once certain conditions are fulfilled, current and voltage pulses propagate along ideal transmission lines with the speed of light. One can reach such a conclusion only when the conductors are assumed to be perfectly conducting, which ...

2020

Field-to-transmission line coupling models

Farhad Rachidi-Haeri, Marcos Rubinstein, Carlo Alberto Nucci

This chapter presents the coupling of lightning electromagnetic fields to overhead and underground lines based on the transmission line approximation. The chapter starts with an introductory section in which the advantages and the drawbacks of three approa ...

IET2020

Impedance and Admittance Formulas for a Multistair Model of Transmission Towers

Farhad Rachidi-Haeri

This article discusses formulas for the surge/ characteristic impedance of vertical conductors. Calculated results of the surge impedance are compared with measured results on vertical conductors and transmission towers. The accuracy of the available time- ...

2020

Towards Quantitative Interpretation of Fourier-Transform Photocurrent Spectroscopy on Thin-Film Solar Cells

Franz-Josef Haug, Michael Elias Stückelberger, Jakub Holovsky, Martin Müller

The method of detecting deep defects in photovoltaic materials by Fourier-Transform Photocurrent Spectroscopy has gone through continuous development during the last two decades. Still, giving quantitative predictions of photovoltaic device performance is ...

2020

Characterisation of Silicon Heterojunction Solar Cells Beyond Standard Test Conditions

Jean Cattin

The global photovoltaic market is mostly dominated by solar cells based on crystalline silicon (c-Si), which are covering 95% of the market. This thesis concerns silicon heterojunction (SHJ), a high-efficiency technology with a 2% market share in 2018, but ...

EPFL2020

The 3D Smith Chart: From Theory to Experimental Reality

Mihai Adrian Ionescu, Andrei Müller

The Smith chart was primarily developed, extended, and refined by Phillip Hagar Smith [1] in a series of works published [2]-[4] between 1939 and 1969. Smith was born in Lexington, Massachusetts, in 1905. He majored in electrical communications at Tufts Un ...

2020

Megawatt power generation of the dual-frequency gyrotron for TCV at 84 and 126 GHz, in long pulses

Stefano Alberti, Damien Fasel, Timothy Goodman, Blaise Marlétaz, Minh Quang Tran, Jean-Philippe Hogge, Ugo Siravo, Christian Moura, Jérémie Dubray, Ioannis Pagonakis, Jonathan Sylvain Masur, Matthieu Toussaint, Jérémy Genoud, Konstantinos Avramidis

In the frame of the TCV Tokamak upgrade, two 84/126 GHz/2 s dual frequency gyrotrons designed by SPC and KIT and manufactured by THALES will be added to the existing EC-System. The first unit has been delivered to EPFL-SPC and tested. In the commissioning ...

2020

Modeling and Design Optimization of Medium Frequency Transformers for Medium-Voltage High-Power Converters

Marko Mogorovic

Novel high-power medium-voltage converter technologies offering galvanic insulation are needed to support the development of the emerging medium-voltage direct-current grids and further improve the performance of various other applications such as traction ...

EPFL2019

Low voltage fast dielectric elastomer actuators

Xiaobin Ji

This thesis contributes to the field of Dielectric Elastomer Actuators (DEAs). DEAs are electrostatically driven soft actuators that are fast, capable of generating large actuation strains, high forces, and present high power density. A wide range of appli ...

EPFL2019

Determination and optimization of material parameters of particle-based LaTiO2N photoelectrodes

Ulrich Aschauer, Yannick Kenneth Gaudy, Sophia Haussener

We developed a validated numerical model capable of predicting the photocurrent-voltage characteristics of oxide and oxynitride particle-based photoelectrodes and identifying the critical parameters affecting the performance of those photoelectrodes. We us ...

Royal Society of Chemistry2018

Using Electromagnetic Time Reversal to Locate Faults in Transmission Lines: Definition and Application of the Mirrored Minimum Energy Property

Farhad Rachidi-Haeri, Mario Paolone, Reza Razzaghi, Zhaoyang Wang, Asia Codino

This paper presents an application of the Electro-magnetic Time Reversal (EMTR) in changing media to identify the fault location along a single-conductor transmission line. It is shown that the time-reversed quantities exhibit a property, called Mirrored M ...

2017