Laser requirements for the design of fast laser-driven semiconductor switches for THz and mm-waves

2021 ◽  
Vol 92 (11) ◽  
pp. 113106
Author(s):  
S. C. Schaub ◽  
Z. W. Cohick ◽  
B. W. Hoff
2014 ◽  
Vol E97.C (8) ◽  
pp. 795-802 ◽  
Author(s):  
Kunihiro KAWAI ◽  
Daisuke KOIZUMI ◽  
Hiroshi OKAZAKI ◽  
Shoichi NARAHASHI

Author(s):  
Jingwen Chen ◽  
Hongshe Dang

Background: Traditional thyristor-based three-phase soft starters of induction motor often suffer from high starting current and heavy harmonics. Moreover, both the trigger pulse generation and driving circuit design are usually complicated. Methods: To address these issues, we propose a novel soft starter structure using fully controlled IGBTs in this paper. Compared to approaches of traditional design, this structure only uses twophase as the input, and each phase is controlled by a power module that is composed of one IGBT and four diodes. Results: Consequently, both driving circuit and control design are greatly simplified due to the requirement of fewer controlled power semiconductor switches, which leads to the reduction of the total cost. Conclusion: Both Matlab/Simulink simulation results and experimental results on a prototype demonstrate that the proposed soft starter can achieve better performances than traditional thyristorbased soft starters for Starting Current (RMS) and harmonics.


Author(s):  
Guy A. E. Vandenbosch ◽  
Xuezhi Zheng ◽  
N. Verellen ◽  
V. K. Valev ◽  
V. V. Moshchalkov
Keyword(s):  

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Martin L. Pall

Abstract Millimeter wave (MM-wave) electromagnetic fields (EMFs) are predicted to not produce penetrating effects in the body. The electric but not magnetic part of MM-EMFs are almost completely absorbed within the outer 1 mm of the body. Rodents are reported to have penetrating MM-wave impacts on the brain, the myocardium, liver, kidney and bone marrow. MM-waves produce electromagnetic sensitivity-like changes in rodent, frog and skate tissues. In humans, MM-waves have penetrating effects including impacts on the brain, producing EEG changes and other neurological/neuropsychiatric changes, increases in apparent electromagnetic hypersensitivity and produce changes on ulcers and cardiac activity. This review focuses on several issues required to understand penetrating effects of MM-waves and microwaves: 1. Electronically generated EMFs are coherent, producing much higher electrical and magnetic forces then do natural incoherent EMFs. 2. The fixed relationship between electrical and magnetic fields found in EMFs in a vacuum or highly permeable medium such as air, predicted by Maxwell’s equations, breaks down in other materials. Specifically, MM-wave electrical fields are almost completely absorbed in the outer 1 mm of the body due to the high dielectric constant of biological aqueous phases. However, the magnetic fields are very highly penetrating. 3. Time-varying magnetic fields have central roles in producing highly penetrating effects. The primary mechanism of EMF action is voltage-gated calcium channel (VGCC) activation with the EMFs acting via their forces on the voltage sensor, rather than by depolarization of the plasma membrane. Two distinct mechanisms, an indirect and a direct mechanism, are consistent with and predicted by the physics, to explain penetrating MM-wave VGCC activation via the voltage sensor. Time-varying coherent magnetic fields, as predicted by the Maxwell–Faraday version of Faraday’s law of induction, can put forces on ions dissolved in aqueous phases deep within the body, regenerating coherent electric fields which activate the VGCC voltage sensor. In addition, time-varying magnetic fields can directly put forces on the 20 charges in the VGCC voltage sensor. There are three very important findings here which are rarely recognized in the EMF scientific literature: coherence of electronically generated EMFs; the key role of time-varying magnetic fields in generating highly penetrating effects; the key role of both modulating and pure EMF pulses in greatly increasing very short term high level time-variation of magnetic and electric fields. It is probable that genuine safety guidelines must keep nanosecond timescale-variation of coherent electric and magnetic fields below some maximum level in order to produce genuine safety. These findings have important implications with regard to 5G radiation.


1991 ◽  
Author(s):  
Fred J. Zutavern ◽  
Guillermo M. Loubriel ◽  
Marty W. O'Malley ◽  
Dan L. McLaughlin ◽  
Wesley D. Helgeson

2007 ◽  
Vol 49 (9) ◽  
pp. 2232-2234
Author(s):  
Yanling Sun ◽  
Shunxiang Shi ◽  
Yanwu Zhu ◽  
Xin Wu

2017 ◽  
Vol 6 (11) ◽  
pp. S3099-S3102 ◽  
Author(s):  
Andrew D. Koehler ◽  
Travis J. Anderson ◽  
Ani Khachatrian ◽  
Anindya Nath ◽  
Marko J. Tadjer ◽  
...  

2016 ◽  
Vol 13 (5-6) ◽  
pp. 374-377 ◽  
Author(s):  
Yunfeng Chen ◽  
Hai Lu ◽  
Dunjun Chen ◽  
Fangfang Ren ◽  
Rong Zhang ◽  
...  

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