Vladislav V. Gavrilin – Engineer, 

PJSC «Radiofizika» (Moscow, Russia)

E-mail: gavrilin@phystech.edu

Yurij V. Krivosheev – Ph.D. (Eng.), Head of Sector, 

PJSC «Radiofizika» (Moscow, Russia);

Lecturer, Chair «Radiophysics and Technical Cybernetics», 

Moscow Institute of Physics and Technology (State University) (Dolgoprudny, Russia);

Lecturer, Chair «Design of Complex Technical Systems», 

Moscow Aviation Institute (State University) (Moscow, Russia)

E-mail: krivosheev-yury@yandex.ru

Alexander V. Shishlov – Ph.D. (Eng.), Head of Department, 

PJSC «Radiofizika» (Moscow, Russia);

Deputy Head of Chair «Radiophysics and technical cybernetics», 

Moscow Institute of Physics and Technology (State University) (Dolgoprudny, Russia) E-mail: shishlov54@mail.ru

Array-fed reflector antenna (AFR) is a system consisting of a large reflector, which provides high directivity of antenna, and a relatively small feed array providing scanning in a narrow angle area (usually till 10°-20°). In this paper a focusing type AFR antenna is considered. In the AFR antenna, a group of feed array elements – so called cluster – is excited in order to form a beam in a given direction of a service area. Such hybrid antennas also are known as Multiple Feed per Beam (MFB) or Focal Array Fed Reflector (FAFR) antennas. Besides, there aremultibeam reflector antennas (MBAs) in which each beam is formed by a single feed. They are called Single Feed per Beam (SFB) reflector antennas. In current work, the AFR MFB antenna with a single offset parabolic reflector is considered. The feed array has hexagonal grid and aperture-type element with Gaussian radiation pattern. Optimal relation between reflector ratio f/D and feed array spacing d/λ is determined. This relation allows to reach the maximum aperture efficiency of the antenna. It is shown that the optimal ratio of array spacing d/λ is equal to 0.5 f/D. Aperture efficiency of the antenna changes insignificantly (±5%) if f/D changes in the range of  ± 30% around the optimal value. In earlier papers it is stated that in SFB MBA, optimal spacing is equal to 1.25 f/D which is 2.5 larger than appropriate array element spacing in MFB AFR antenna.

Gavrilin V.V., KrivosheevYu.V., Shishlov A.V. Optimal ratio between feed array spacing and reflector focal length in array-fed reflector antenna. Radiotekhnika. 2020. V. 84. № 10(19). P. 41−. DOI: 10.18127/j00338486-202010(19)-04 (In Russian).

1. Rudge A.W., Withers M.J. New Technique for Beam Steering with Fixed Parabolic Reflectors. Proceedings IEE. 1971. 118. Р. 857-863.
2. Alimova L.I., Kinber B.E., Klassen V.I., Shishlov A.V. Vozmozhnosti shirokougol'nogo skanirovanija v gibridnyh zerkal'nyh antennah. Radiotehnika i jelektronika. 1981. T. 26. № 12. S. 2500-2510 (In Russian).
3. Mailloux R.J. Hybrid antennas. The Handbook of Antenna Design. Editors A.W. Rudge et al. London. 1982. P. 415-465.
4. Space Antenna Handbook. Editors W.A. Imbriale, S. Gao, L. Boccia. John Wiley & Sons, Ltd. 2012. 744 p.
5. Rao S., Shafai L., Sharma S. Handbook of Reflector Antennas. V. III. Applications of Reflectors. Artech House. 2013.
6. Galindo-Israel V., Lee S.-W., Mittra R. Synthesis of a Laterally Displaced Cluster Feed or a Reflector Antenna with Application to Multiple Beams and Contoured Patterns. IEEE Transactions on Antennas and Propagation. March 1978. V. AP-26. № 2. P. 220-228.
7. Lam P.T., Lee S.W., Change D.C.D., Lang K.C. Directivity Optimization of a Reflector Antenna with Cluster Feeds. A Closed-Form Solution. IEEE Transactions on Antennas and Propagation. 1985. V. AP-33. № 11. P. 1163-1174.
8. Vilenko I.L., Krivosheev Ju.V., Shishlov A.V. Gibridnye zerkal'nye antenny s obluchajushhimi aktivnymi fazirovannymi reshetkami.  Antenny. 2011. Vyp. 10 (173). S. 22-42 (In Russian)
9. Shishlov A.V., Vilenko I.L., Krivosheev Yu.V. Active Array Fed Reflector Antennas. Practical Relations and Efficiency. Proceedings of the 6-th European Conference on Antennas and Propagation. Prague. March 2012. 5 p.
10. Shishlov A.V., Vilenko I.L., Krivosheev Y.V. Asymptotic theory, design and efficiency of array-fed reflector antennas. Phased Array Systems and Technology. IEEE International Symposium. Boston-Waltham. 2013. P. 320-327.
11. Korbanskij I.N. Antenny. M.: Jenergija. 1973 (In Russian).
12. Anpilogov V.R., Shishlov A.V., Jejdus A.G. Mnogoluchevye antennye sistemy HTS. Tehnologii i sredstva svjazi. 2013, № 6−2. S. 54–67 (In Russian