61-68

UDC 621.391
DOI: 10.15350/2306-2819.2017.3.61

FOCUSING OF ELECTROMAGNETIC RADIATION IN THE DISSIPATIVE MEDIUM

D. A. Vedenkin¹, Yu. E. Sedelnikov,² A. R. Nasybullin¹,
¹Volga State University of Technology,
3, Lenin Square, Yoshkar-Ola, 424000, Russian Federation
E-mail: aydar.nasybullin@mail.ru; denis_ved@mail.ru
²Kazan National Research Technical University named after A. N. Tupolev-KAI,
10, K. Marx Street, Kazan, 420111, Russian Federation
E-mail: sedhome2013@yandex.ru

ABSTRACT

Introduction. Under natural operating conditions, antenna systems, using the focused aperture principle, necessarily work in dissipative mediums. Medium parameters have a considerable effect on focused electromagnetic field characteristics. Consideration of the influence of dissipative propagation medium parameters will allow improving focused arrays characteristics. The purpose of the work is the calculation and analysis of the characteristics of microwave complexes, using the focused aperture principle and operating in a lossy medium. Mathematical modeling was implemented for a random volume sparse antenna array, focused in the near radiated field zone for different values of the medium attenuation coefficient. The comparison was made with a unit radiator, located in the imaginary centre of the random array with the equal radiated power. Results. It is shown that dissipative characteristics have a considerable effect on radiation focusing and the subsidiary maximums level of the focused field. Estimates of the critical value of the attenuation coefficient, when the focused field intensity decreases to 0,707 from the maximum intensity, obtained in the lossy medium are given. The comparison of electromagnetic field intensities from the focused array with the field from the unit radiator showed that they have the same tendency to attenuation. Besides the location of array radiators in space is important: the shorter way the electromagnetic wave in the lossy medium passes i.e. the nearer to the focusing point radiators are, the larger the field intensity from the focused array is in comparison with the unit radiator and vice versa: the farther the radiators are, the smaller the intensity becomes. Conclusion. The electromagnetic field propagation medium attenuation coefficient has a significant impact on the focusing effect. In order to increase the focused field level it is necessary to place partial radiators of the focused antenna array in the forward semisphere, relative to the unit radiator, that will allow increasing the field intensity in the focusing point.

KEYWORDS

focused aperture; dissipative medium; focusing area; side radiation level

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ACKNOWLEDGMENT

The work was carried out with financial support from the Russian Science Foundation (Grant №15-19-10053).

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For citation: Vedenkin D. A., Sedelnikov Yu. E., Nasybullin A. R. Focusing of Electromagnetic Radiation in the Dissipative Medium. Vestnik of Volga State University of Technology. Ser.: Radio Engineering and Infocommunication Systems. 2017. No 3 (35). Pp. 61-68. DOI: 10.15350/2306-2819.2017.3.61