Radiotekhnika
Publishing house Radiotekhnika

"Publishing house Radiotekhnika":
scientific and technical literature.
Books and journals of publishing houses: IPRZHR, RS-PRESS, SCIENCE-PRESS


Тел.: +7 (495) 625-9241

 

Power efficiency of the algorithm of “compression” of the beam pattern of the digital PAA

Keywords:

V. P. Kortnev – Ph.D. (Eng.), Senior Research Scientist
E-mail: valery.Kortnev@yandex.ru
A. E. Krasnov – Head of Laboratory, JSC “Phazotron–NIIR Corporation” (Moscow)


In earlier published literature mentioned in this article the algorithm of "compression" of the beam pattern (BP) of digital phased array antenna (PAA) by 3…100 times is described, the variant of physical interpretation of the mechanism of compression of BP is provided as the virtual increase in interelement spacing at the fixed number of radiators as a result of which at sharpening of the BP there are grating lobes in size matching the main maximum of the real beam pattern (BPr).
The purpose of the work is the research and assessment of power losses because of the reduction of the directivity factor (DF) of digital phase array antenna and losses of the output “signal/noise” ratio at fixed transformations in the algorithm of “compression” of the beam pattern.
Taking into account above mentioned, these researches were carried out in two directions, first of which was devoted to studying of the compression procedure (significant sharpening) of the beam pattern of digital PAA and its influence on the directivity factor of phased antenna arrays. The studied procedure lies in the fact that as it was mentioned above, the aperture of the antenna of digital phased antenna array can be transformed virtually, without changing its actual physical dimensions and the number of radiators. At the same time the distance between radiators can be increased so that it can make any desirable number of half waves of the applied signal. At increase in interelement spacing up to the value exceeding λ /2 the aperture of PAA becomes discrete that defines the emergence of the grating lobes (GL) in the “compressed” beam pattern (BPc). The value (capacity, voltage) of maxima of GL at any “compression” ratio (CR) for any angular position is identical and equal to the main maximum of real BP. The width of GL is equal to the width of the main maximum of BPc.
Taking into account the results of mathematical modeling and proceeding from the principles of work of PAA, it is possible to conclude that the quantity of maxima of BP (nD) is equal to the "compression" ratio. Proceeding from the aforesaid, it follows that all GL contain rather big power in the sum.
The researches carried out within the work showed that the source of this power is a peripheral part of the main lobe of the real BP therefore the DF in BPc does not depend on CR and is equal to the DF of the real BP. The second direction of the research of power of the algorithm of "compression" of BP is devoted to the definition of the signal/noise ratio at the algorithm output, i.e. at the output of the device of suppression of BP. As the remultiplier of the GL and PBc (the nonlinear device) is used as the suppressor in this case for definition of the output signal/noise ratio the equation was derived which solution showed that at the output signal/noise ratio ≈ 1 the power losses of the suppressor L ≈ 6 dB, and at the output signal/noise ratio ≈ 3,5 L ≈ 1 dB. Therefore, for compensation of losses it is necessary to increase the power of system, having applied, for example, the Doppler filtering before a remultiplier or to use other ways providing increase in the signal/noise ratio at the output of the algorithm of “compression” of the beam pattern of PAA and to implement the required angular superresolution.

References:
  1. Patent RF № 2507647. Fazirovannaya antennaya reshetka s upravlyaemoj shirinoj diagrammy napravlennosti / V.P. Kortnev. Opubl. 20.02.2014. Byul. № 5.
  2. Kortnev V.P. Algoritmicheskij metod «szhatiya» DNA RLS // Antenny. 2009. № 12. S. 13–17.
  3. Kortnev V.P. E'ffektivnost' algoritmicheskogo «szhatiya» diagrammy napravlennosti FAR pri ispol'zovanii shirokopolosnogo signala // Antenny. 2017. № 3. S. 57–63.
  4. Dobyrn V.V., Nemov A.V. Algoritmicheskij metod obuzheniya DN passivnoj FAR // Izvestiya VUZov. Ser. Radiotekhnika. 1998. Vyp. 1. S. 61–67.
  5. Vendik O.G. Antenny s nemekhanicheskim dvizheniem lucha. M.: Sov. radio. 1965.
  6. Zadorozhnyj V.V., Larin A.Yu., Litvinov A.V., Pomysov A.S. Metod obuzheniya diagrammy napravlennosti tsifrovoj antennoj reshetki // Uspekhi sovremennoj radioe'lektroniki. 2013. № 8. S. 94–99.
  7. Ajzenberg G.Z. Antenny ul'trakorotkikh voln. M.: Svyaz'izdat. 1957.
  8. Spravochnik po radiolokatsii. Kn. 1 / Pod red. M.I. Skolnika. M.: Tekhnosfera. 2015.
  9. Korbanskij I.N. Antenny. M.: E'nergiya. 1975.
  10. Ajzenberg G.Z. Antenny ul'trakorotkikh voln. M.: Svyaz'izdat. 1957.
  11. Sovremennaya radiolokatsiya / Pod red. Yu.B. Kobzareva. M.: Sov. radio. 1967.
  12. Barton D. Radiolokatsionnye sistemy: Per. s angl. P. Gorokhova, O. Kazakova, A. Tupitsyna. M.: Voennoe izdatel'stvo. 1967.

© Издательство «РАДИОТЕХНИКА», 2004-2017            Тел.: (495) 625-9241                   Designed by [SWAP]Studio