Accounting for Nonuniformity of the Electromagnetic Field when Calibrating Thin Dipole and Loop Antennas in Four-Wire Sources

Author(s):  
V. I. Lukyanov ◽  
M. V. Vasilyeva
Metrologiya ◽  
2021 ◽  
pp. 60-74
Author(s):  
V. I. Lukyanov ◽  
M. V. Vasilyeva

The influence of nonuniformity of electric and magnetic fields on the calibration accuracy of dipole and loop antennas in field sources based on four-wire transmission lines is theoretically investigated. The paper proposes to take into account the influence of the nonuniformity of the electromagnetic field of a four-wire source when calibrating thin dipole and loop antennas using the equivalence coefficients. The use of these coefficients, taking into account the distributions of the field in the source and the current on the antenna conductors, can significantly weaken the requirement for field uniformity when calibrating antennas. For some common types of antennas, formulas are derived for the equivalence coefficients in the approximation of a four-wire source by an infinite line. Approximation formulas, simplified for engineering calculations, are obtained.


Energies ◽  
2019 ◽  
Vol 12 (7) ◽  
pp. 1275 ◽  
Author(s):  
Guoming Wang ◽  
Woo-Hyun Kim ◽  
Gyung-Suk Kil ◽  
Dae-Won Park ◽  
Sung-Wook Kim

Prediction of lightning occurrence has significant relevance for reducing potential damage to electric installations, buildings, and humans. However, the existing lightning warning system (LWS) operates using the threshold method and has low prediction accuracy. In this paper, an intelligent LWS based on an electromagnetic field and the artificial neural network was developed for improving lightning prediction accuracy. An electric field mill sensor and a pair of loop antennas were designed to detect the real-time electric field and the magnetic field induced by lightning, respectively. The change rate of electric field, temperature, and humidity acquired 2 min before lightning strikes, were used for developing the neural network using the back propagation algorithm. After observing and predicting lightning strikes over six months, it was verified that the proposed LWS had a prediction accuracy of 93.9%.


1993 ◽  
Vol 3 (3) ◽  
pp. 363-371 ◽  
Author(s):  
A. Konrad ◽  
I. A. Tsukerman

2020 ◽  
pp. 27-33
Author(s):  
Boris A. Veklenko

Without using the perturbation theory, the article demonstrates a possibility of superluminal information-carrying signals in standard quantum electrodynamics using the example of scattering of quantum electromagnetic field by an excited atom.


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