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The aim of this paper is to investigate the impact of the ground‐material uncertainty on the properties of electromagnetic fields generated by lightning strikes. Although several analytical as well as numerical approaches have been proposed throughout previous years for the prediction of lightning‐induced fields, these are mostly applied within a fully deterministic context, thus overlooking the degree...
Machine-type communication (MTC) provides a potential playground for deploying machine-to-machine (M2M), IP-enabled ‘things’ and wireless sensor networks (WSNs) that support modern, added-value services and applications. 4G/5G technology can facilitate the connectivity and the coverage of the MTC entities and elements by providing M2M-enabled gateways and base stations for carrying traffic streams...
Split-ring resonators (SRRs) are fundamental elements of metamaterials, which exhibit attractive properties and find various electromagnetic applications. In this paper, we consider the inclusion of SRRs for improving the performance of various antennas, with respect to their radiation patterns, electrical size or wideband response. The provided results verify that incorporating SRRs in the radiator...
Deterministic schemes are usually unable to predict random media uncertainties and as a result produce unreliable outcomes in this kind of problems. In this work, we present a novel finite difference time domain (FDTD) technique that manages to calculate the statistics of the involved field quantities, considering that the variability of random media is known. The proposed method is applied in polar...
Uncertainties characterizing the per-unit-length parameters of transmission lines (TL) may have a significant impact on the properties of the propagating voltage and current waves that deterministic models tend to overlook. In this paper, we present an unconditionally-stable finite-difference time-domain (FDTD) algorithm that calculates the statistics of the involved field quantities, provided that...
The latest new generation passive optical network (NG-PON) standard, known as 10-gigabit-capable passive optical network (XG-PON), enables a very promising architecture that offers 10 Gbps nominal data delivery ratio in the downstream direction. The optical line terminal (OLT) is located within the CO and constitutes the main decision-making tank of the PON. OLT applies a dynamic bandwidth allocation...
Aiming at the minimization of numerical dispersion effects in finite-difference time-domain (FDTD) simulations, we investigate the potential of introducing frequency-dependent coefficients in the approximations of differential operators. The proposed methodology exploits some previous results on optimized finite-differences, but initially avoids the necessity for selecting a specific optimization...
We present a computational framework for the prediction of electromagnetic fields in lightning problems which, unlike common methodologies, can efficiently incorporate the statistical variations that characterize the ground electric parameters. Our full-wave technique is based on the three-dimensional (3D) extension of the stochastic finite-difference time-domain (S-FDTD) method, and enables the extraction...
When studying electromagnetic field problems like lightning phenomena, the efficiency of the adopted model relies on the accurate and rapid calculation of Sommerfeld type Integrals (SI). In the present work we propose an efficient method for calculating them, based on their numerical evaluation along a deformed path of integration. The method is combined with an interpolation technique in order to...
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