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Electromagnetic radiation from vertical dipole antennas near air–lossy soil interface—a finite‐difference time‐domain simulation
Author(s) -
Paran Kian,
Kamyab Manoochehr
Publication year - 2005
Publication title -
international journal of numerical modelling: electronic networks, devices and fields
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.249
H-Index - 30
eISSN - 1099-1204
pISSN - 0894-3370
DOI - 10.1002/jnm.567
Subject(s) - finite difference time domain method , perfectly matched layer , lossy compression , time domain , acoustics , antenna (radio) , dipole , dipole antenna , fourier transform , optics , physics , computational physics , computer science , mathematics , mathematical analysis , telecommunications , quantum mechanics , computer vision , artificial intelligence
Radiation from vertical dipole antennas, which are located over or under the surface of lossy earth, is analysed by the finite‐difference time‐domain (FDTD) method in cylindrical coordinates. A novel generalized perfectly matched layer (PML) has been developed and used for the truncation of the lossy soil. In order to decrease the memory requirements and for having an accurate modelling, an efficient ‘non‐uniform’ mesh generation scheme is used. The excitation is considered in the form of sine carrier modulated by Gaussian pulse (SCMGP) and in each time step, computation is limited to that part of the mesh where the radiated pulse is passing (computational window). This could considerably reduce the required CPU time. In this manner, large‐scale problems can be solved and the values of radiated field at far distances (up to 500λ 0 in this work) can be obtained directly by the FDTD method. The frequency‐domain results are calculated from the obtained time‐domain results by taking the Fourier transform. The spatial distributions of the amplitude and phase of radiated field are shown in illustrations for different types of soil and different positions of antenna. The influence of the lossy soil on dipole's admittance is also shown. Copyright © 2005 John Wiley & Sons, Ltd.