Aerospace and Electronic Systems Magazine August 2016 - 35

Shifrin consisted in the fact that the laboratory nominally was part of the head Moscow institute, and employees of this laboratory were paid salaries like those in Moscow. These were much more than ours. But the main thing was that, by agreement with the Chief designer, plans of this laboratory work were outlined by me. The first problem I stated for the laboratory team was to define the statistics of the field impinging on the giant (kilometer in length) receiving antenna of over-the-horizon radar with the aim of upgrading this antenna if it appeared to be reasonable. Interesting results were obtained for the variance of errors at the inputs of dipoles of this antenna; but, unfortunately, this work was brought to a close due to my unexpected retirement from the Academy. It's a great pity... In this article, I restricted myself to consideration of works on SAT, carried out by myself alone or jointly with my coworkers. I paid special attention to my monograph [5]. Its publication essentially stimulated the investigations in the area of SAT, and by now, in the literature, a lot of works devoted to different aspects of this theory are published. Among them are several monographs (see, e.g., [29], [30]) that develop the ideas of SAT. The majority of the works treat the direct external problems. But there also are quite a few works wherein the direct internal problems (i.e. the mechanism of the randomness formation is studied), inverse problems of different kinds, etc. are considered. The state-of-the-art of SAT is rather thoroughly given in my survey [31]. ACKNOWLEDGEMENTS CONCLUSIONS The presence of randomness in an antenna, being sometimes rather serious, changed the way many specialists looked at the antenna as at a certain iron construction with rigidly fixed parameters. In reality, antenna parameters often appear to be random, and it is natural to describe them in the language of either the probability theory or the theory of random functions. This impelled me in the early 1960s to create the SAT-the theory of antennas with random sources. Grounds of the new theory were developed on the example of the simplest antenna-a linear antenna with a uniform amplitude distribution and normally distributed phase errors. Studied were dependences of the antenna's main statistical characteristics on the parameters of phase errors, their variance, and correlation radius. Simple formulas for the calculation of a number of statistical effects were obtained. The numerical, rather useful for practice, estimates of these effects are given. Simultaneously, the terminology, definitions, and notions inherent in SAT are introduced. The theory, which was developed for the far-field region of the simplest system, was generalized to different types of linear and bidimensional, continuous, and discrete, antenna systems, as well as to the Fresnel region and antennas focused to this region. This essentially extended the theoretical basis of the new theory and significantly expanded the area of its applicability. In the course of these investigations, a number of effects were revealed, which showed the difference between SAT and ordinary antenna theory. The SAMT was built. As experience shows, today, designing of modern large expensive antennas-a choice of a reasonable scheme for the building, accounting for real and attainable characteristics, taking into account AUGUST 2016 randomness of construction and exploitation character (deformations, damages, failures, etc.)-are unthinkable without employing, to this or that extent, the SAT, its approaches and results. On the basis of SAT, reasonable requirements for antenna production, tolerances, stability of antenna elements, and their reliability are formulated. An equally important aspect of the SAT application is constituted of issues connected with estimation of the antenna efficiency, its characteristics at work in complicated conditions where inhomogeneities of the troposphere, ionosphere, plasma formations, ground roughness, multibeamness, etc. influence the efficiency of the antenna. As time passed, the SAT essentially advanced, and today there are good reasons to consider it one of the important directions of the usual antenna theory. The concepts, methods, approaches, and terminology used in this theory have already became natural and usual not only for antenna specialists, but also for those who work in other areas. Elements of SAT are inserted in many books on antennas, published in the USSR after 1970. The continuous progress of science, its different areas (radioelectronics, radio wave propagation, acoustics, optics, medicine, etc.) continues to identify more and more new problems, which by their essence are close to the ideas of SAT. This circumstance makes further investigations in this area rather urgent. I consider it my pleasant duty to express my sincere gratitude to my colleagues, who contributed to the extension of the statistical antenna theory-Leonid G. Kornienko, Vadim I. Zamyatin, Vladimir A. Usin, Peter S. Trashkov, Yuri M. Borodavko, Vladimir A. Nazarenko, Vladimir V. Dolzhikov, et al. I also appreciate Erv C. Gangl and Yuri I. Abramovich for very useful advice at stages of the paper preparation. Especially I am grateful to my wife and colleague Nina G. Maksimova, as only owing to her invaluable daily help, was I able, in spite of perceptible problems with health, to prepare this paper. REFERENCES [1] [2] [3] [4] [5] [6] [7] IEEE A&E SYSTEMS MAGAZINE Ruze, J. The effect of aperture errors on the antenna radiation pattern. Supplemento al Nuovo Cimento, Vol. 9, 3 (1952), 364. Robieux, J. Influence de la precision de fabrication d`une antenne sur ses performances. Annales de Radioelectricite, Vol. 11, 43 (1956), 29. Chernov, L. A. 1958, Wave Propagation in a Random Medium. New York: McGraw-Hill, 1960. Moscow: AS USSR, 1958. Shifrin, Y. S. Field Statistics of the Linear Antenna. Monograph. Russia: ARTA, 1962 (in Russian). Shifrin, Y. S. Statistical Antenna Theory. USA: Golem Press, 1971. Issues of the Statistical Antenna Theory. Moscow: Sovetskoe Radio, 1971 (in Russian). Shifrin, Y. S., Chernij, P. B., Tikhomirov, Y. A., Tarasov, V. A., and Trashkov, P. S. Experimental Investigations of the Long-Distance Tropospheric Propagation of Ultrashort Radiowaves. Kharkov: ARTA, 1964, (in Russian). Armand, N. A., Vvedenskij, B. A., Shifrin, Y. S. et al. (total 25 authors). Long-Distance Tropospheric Propagation of USW. B. A. 35

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