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The Electromagnetic Field of the Underground SLF/ELF Horizontal Electric Dipole Located in the Isotropical Earth-ionosphere Wave Guide

Author: LiuDuJuan
Tutor: GuanBoRan
School: Hangzhou University of Electronic Science and Technology
Course: Circuits and Systems
Keywords: Ultra-low frequency / ELF Earth - ionosphere waveguide Reciprocity theorem Horizontal electric dipole
CLC: TN814
Type: Master's thesis
Year: 2010
Downloads: 86
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Abstract

Characterized by ultra-low frequency / very low frequency segment of electromagnetic waves the stable propagation characteristics, attenuation is relatively small, the ability to penetrate. The use of ultra-low frequency / ELF waves can penetrate into the deep seawater, the characteristics of the signal can be received in the deep, it can be used in submarine submarine communication, thereby enhancing the security of the submarine, and the ability to ensure that the anti-submarine smooth communication, but it also can command other underwater equipment and devices. The ultra-low / very low frequency waves can be relatively deep infiltration into objects such as rocks, soil, and the attenuation rate is relatively small, and thus can be used to command a large area in the depths of the bunker. This band of electromagnetic wave propagation in the Earth - ionosphere can be very far distance signal transmission, and even the world, so it is very suitable for long-distance communications. Because it is not susceptible to interference ionospheric disturbances, even a nuclear explosion, it will not be serious interference, so in future wars under extreme environmental conditions, ultra-low frequency / ELF waves can become a large area of ??the Emergency Command Control Communications an important means. It also can be used to predict earthquakes, geological survey, and many other aspects, so further study the electromagnetic wave propagation characteristics of this band has a very important significance. In this thesis, the ultra-low frequency / very low frequency segment, horizontal electric dipole electromagnetic fields generated by the Earth - ionosphere waveguide. Specific analysis of electromagnetic fields generated by vertical electric dipole located on the ground were in the ground and underground, and is located on the ground of a vertical magnetic dipole, respectively, in the above-ground and underground electromagnetic fields generated by these same aspects consider horizontal electric dipole situation. Has been focus of this paper is to use the vertical electric dipole and vertical magnetic dipole electromagnetic fields generated by the Earth - ionosphere waveguide and the reciprocity theorem to discuss the horizontal electric dipole located underground on the ground, underground, and ionization the electromagnetic field generated in the layer. The paper first introduced in the ultra-low frequency / very low frequency segment, the ionosphere and the ground for this band of electromagnetic waves have a better reflection characteristics of the electromagnetic waves in the Earth - ionosphere waveguide propagation, so must consider ionospheric Existence. Here in order to facilitate the study of ionospheric idealized as having a clear boundary of the ionosphere, i.e. having a specific surface impedance of the ionosphere, the same time, the ground also has a specific surface resistance as another reflection wall. Earth - ionosphere waveguide ionosphere and ground idealized spherical with the same center. Propagation of electromagnetic waves in the Earth - ionosphere waveguide two reflecting walls of the ground and the ionosphere multiple reflections to guide the forward spread. In this thesis only consider the Earth - ionosphere waveguide is isotropic. Deduced in this manner - the ionosphere waveguide in the ground vertical electric dipole and vertical magnetic dipole electromagnetic fields generated on the ground and under the ground, while the application of the reciprocity theorem obtained in the ground - the ionosphere waveguide electromagnetic field, located on the ground floor of a horizontal electric dipole in the ground, underground, and ionosphere. Electromagnetic fields generated by the horizontal electric dipole in the earth - ionosphere waveguide from the underground and the ionosphere, two aspects were discussed and compared.

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