Aerospace and Electronic Systems Magazine August 2016 - 26

Pioneer Award finally, finding out how variations in the fluctuation parameters (α and ρ) influence the statistical characteristics of antennas. It was also essential to obtain the solution of the problems in a form convenient for engineers-practitioners, and, as possible, suitable for any errors and any radii of their correlation. Simultaneously, it was necessary to introduce new terms, notions, and definitions. Note that in those days, in the early 1960s, there were no computerized computational techniques at ARTA. This significantly complicated the calculations. In particular, a lot of effort went into calculating and tabulating integrals by hand using only primitive means. Nevertheless, already in 1962, I published the monograph, Field Statistics of Linear Antenna [4]. In this monograph, the key results of the theory under development were presented. For this reason, 1962 could be considered the year of the birth of SAT. Unfortunately, the monograph remained little known, as it was published only by the ARTA departmental publishing house. Later, after this material was significantly elaborated and supplemented, I submitted it as a doctoral thesis called "Statistical Antenna Theory" for a doctor of technical sciences degree and defended it in 1964. In 1966, I worked the thesis into a book called Issues of Statistical Antenna Theory and submitted the manuscript to the Moscow publishing house Sovetskoe Radio. For some reason, unknown to me, the book was not issued until 1970 [5]. In early 1972, unexpectedly for me, several copies of my book translated into English and titled Statistical Antenna Theory arrived at the post office of ARTA from the United States of America (USA). It turned out that the book was translated and published by a well-known specialist in the field of applied electromagnetics, Petr Beckman. (I recall with pleasure that Petr Beckman also sent me, as a gift, a big package of books he wrote on physics, mathematics, and music.) Of course I was pleased that the book had been translated into English. Moreover, the first sentence in Beckman's foreword was: "There is an impressive list of features that make this book outstanding." However, I could not stay glad for a long. The fact that this book was published abroad and then delivered directly to the ARTA post office at that time-the time of the "iron curtain"-caused a stir among the ARTA leadership. The very disturbed Commander of ARTA called me into his office and demanded that I explain how this could happen. Of course I could give no explanations. Our leadership calmed down after the higher military leadership from Moscow appeared to approve the translation and publication of the book in the USA and said to our Commander: "This is the first case in the Anti-Aircraft Defence Forces, and you may be proud of this." Mean power RPs of the linear antennas for different α and c. (a) at different α and c = 0.5. (b) at different с and α = 1. any phase errors' parameters was obtained for it. Results of calculations by this formula are given in Figure 3 (a) and (b) for a number of values of variance α, and relative correlation radius of phase errors c = 2ρ / L, (where L is the antenna length). In these figures, the value for the mean power RP (the bar means averaging), in dB, is plotted on the y-axis; the generalized angle ψ = (πL / λ)sin θ where θ is the angle counted from the normal to the axis of a linear antenna is plotted on the x-axis, and λ is the working wavelength. The value for the power radiated by the antenna in the absence of errors was assumed to be unity (0 dB). Note that plots and numerical estimates, given in the book, are obtained given a Gaussian shape of the correlation coefficient of phase errors. Along with this, considerable attention in the book is paid to a comparison of results for Gaussian and exponential forms of errors' correlation coefficients. Issues of calculation of statistical antenna characteristics, given an arbitrary form of errors' correlation coefficient, are also discussed. When considering these figures and a series of those similar to them, it can be concluded that: C C C THE BOOK " STATISTICAL ANTENNA THEORY " From here, I will dwell on the contents of the book Statistical Antenna Theory [5], since it properly reflects the results of investigations I carried out while creating the SAT grounds. The book consists of three parts. In the first part, the grounds of the SAT are set forth. As stated previously, they were developed using a linear antenna with a uniform amplitude distribution and random phase errors-the same model as in [4]. Everything begins with the consideration of the mean power radiation pattern (RP) of the antenna. A general formula, suitable for 26 Figure 3. the presence of errors leads to RP smoothing-filling in nulls and a decrease in the field in the main maximum direction (MMD); with the increase in the variance of errors, the character of RP gradually varies from oscillating to monotonic decreasing; simultaneously, the value of the power radiated in the MMD decreases; with the increase in the correlation radius of errors, the RP approaches an error-free radiation pattern; simultaneously, the power radiated in the MMD increases. In addition to the general case, the mean RP characters for four limiting cases: small and large errors (α ≪ 1 and α ≫ 1) and their small and large correlation radii (c ≪ 1 and c ≫ 1), were considered. I restricted here a case of small errors by the condition a  0.25 (the standard deviation of errors s0  30°), and a case of small correlation radii by the condition с 0.2 (r0.1 L ). Of special practical interest is the case of small errors. So let us treat it in a little more detail. Figure 4 shows curves that illustrate IEEE A&E SYSTEMS MAGAZINE AUGUST 2016

Table of Contents for the Digital Edition of Aerospace and Electronic Systems Magazine August 2016