نتایج جستجو برای: distortion wave

تعداد نتایج: 258678  

Journal: :Physical review letters 2014
T Huber S O Mariager A Ferrer H Schäfer J A Johnson S Grübel A Lübcke L Huber T Kubacka C Dornes C Laulhe S Ravy G Ingold P Beaud J Demsar S L Johnson

Using femtosecond time-resolved x-ray diffraction, we directly monitor the coherent lattice dynamics through an ultrafast charge-density-wave-to-metal transition in the prototypical Peierls system K(0.3)MoO(3) over a wide range of relevant excitation fluences. While in the low fluence regime we directly follow the structural dynamics associated with the collective amplitude mode; for fluences a...

2012
João C. Faria António P. Martins

Cascaded multilevel inverters offer several advantages over other multilevel structures: modularity, high voltage capability, reliability. Additionally, a large number of cascaded inverters using a square wave modulation method allow low losses in the inverter and low harmonic distortion in the output voltage. This paper analyzes the main features of one of these modulation methods especially i...

2004

For one thing, some measurements which are very hard in the time domain are very easy in the frequency domain. Consider the measurement of harmonic distortion. It's hard to quantify the distortion of a sine wave by looking at the signal on an oscilloscope. When the same signal is displayed on a spectrum analyzer, the harmonic frequencies and amplitudes are displayed with amazing clarity. Anothe...

Journal: :SIAM Journal of Applied Mathematics 2011
Stephen M. Cox Meng Tong Tan Jun Yu

Class-D audio amplifiers are particularly efficient, and this efficiency has led to their ubiquity in a wide range of modern electronic appliances. Their output takes the form of a high-frequency square wave whose duty cycle (ratio of on-time to off-time) is modulated at low frequency according to the audio signal. A mathematical model is developed here for a second-order class-D amplifier desi...

2018
A. Ramesh Chandra Sekhar Siva Kumar

Received Sep 19, 2017 Revised Dec 30, 2017 Accepted Jan 17, 2018 Penetration of multilevel inverters (MLI) in to high power and medium voltage application has been increasing because of its advantages. A conventional two level inverter has high harmonic distortion which gives poor power quality. Lot of topologies has been developed to overcome the drawbacks of two level inverter. These topologi...

2014
Puladasu sudhakar

The main purpose of this paper is to discuss the basic understanding of active and reactive power flows in photovoltaic (PV) based distributed generation injected power system and how these power flows will influence the performance and stability of a power system. the harmonic currents injected into the utility grid may be a serious problem since they could lead to unacceptable levels of wave ...

Journal: :Physical review letters 2013
Hyun-Jung Kim Jun-Hyung Cho

The precise driving force of the phase transition in indium nanowires on Si(111) has been controversial whether it is driven by a Peierls instability or by a simple energy lowering due to a periodic lattice distortion. The present van der Waals (vdW) corrected hybrid density functional calculation predicts that the low-temperature 8×2 structure whose building blocks are indium hexagons is energ...

Journal: :CoRR 2011
Labib Francis Gergis

Efficient RF power amplifiers used in third generation systems require linearization in order to reduce adjacent channel inter-modulation distortion, without sacrificing efficiency. Digital baseband predistortion is a highly cost-effective way to linearize power amplifiers (PAs). New communications services have created a demand for highly linear high power amplifiers (HPA's). Traveling Wave Tu...

2013
V. Prabhu

Multilevel inverters have an attracted a great deal of attenuation in medium voltage and high power application. Due to their lower switching losses, EMI, high efficiency. Among the several multilevel inverters topology it is more attractive due to the simplicity of control. This paper proposes to CHMLI output voltage level is increase to reduced total harmonic Distortion. Hence the paper mainl...

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