S.M. Garanin1, A.S. Belov2, A.M. Polyashov3, L.I. Bakina4, A.R. Blokhin5

1–5 FSUE RFNC «All-Russian Research Institute of Experimental Physics» (Sarov, Russia)
1 garanin_s.m@mail.ru, 2 aBelov@niiis.nnov.ru, 3 frustum@rambler.ru, 4 lyubov1g@yandex.ru, 5 blohin.artem2001@gmail.com

A distinctive feature of field scattering from any antenna, compared to simple bodies, is that when an electromagnetic wave from an external radar station impinges on the antenna system, the formation of the scattered field can be described as the result of the summation of two components: structural and antenna. The first component is determined by the shape, inhomogeneities, and material properties. The antenna component is divided into resonant and re-radiated components. The resonant scattering component is a consequence of the radiation of resonant currents excited on the antenna. The re-radiated component is determined by the quality of antenna matching, i.e., the ratio of the antenna input impedance, load impedance, and line impedance. In the case of comparable frequencies of the radar station and the onboard radio technical system (which includes the antenna), the effective scattering surface of the entire aircraft increases dramatically. Therefore, when designing antennas, it is necessary not only to address the issue of optimizing radio technical characteristics related to the reception and radiation of electromagnetic waves but also to tackle the problem of minimizing scattering characteristics from these antennas. The challenge arises in reducing the radar visibility of the antenna within its operating band, as this task is connected with the necessity to maintain the requirements for its radiation characteristics.

Since the antenna system as part of the aircraft makes a significant contribution to the overall radar visibility, and often this contribution is decisive, the issue of developing methods, materials, and designs that can reduce their effective scattering surface remains relevant at present. The main objective of this work is to investigate the possibility of using broadband radar-absorbing materials in the designs of typical omnidirectional antennas for onboard satellite navigation systems to reduce their radar visibility while maintaining the required radiation patterns. The research was conducted through computational and theoretical modeling using the numerical method for solving Maxwell’s equations known as «Finite Difference Time Domain» (FDTD). The correctness of the numerical modeling results was confirmed by experimental studies of the scattering characteristics of the prototypes of the studied antennas using a laboratory setup for measuring the effective scattering surface.

Based on the results of the conducted research, the possibility of using radar-absorbing materials in the design of onboard antennas to reduce their radar visibility has been confirmed. The radar-absorbing material placed on structural elements that minimally participate in radiation formation allows reducing the radar visibility of antennas by 4–10 dB in a wide frequency band while having a negligible impact on their radiation patterns within the operating frequency ranges. It has been established that the optimal locations for placing radar-absorbing materials are the outer elements of antenna housings – pedestals, resonator walls, mounting flanges, etc. The use of radar-absorbing materials on the radiating elements of low-directive antennas in most cases leads to a significant reduction in gain and should be applied with caution. To ensure additional reduction of the effective scattering surface, it is permissible to place radar-absorbing materials on the structural elements of radiators, however, in this case, additional measures must be taken to reduce the degradation of the antenna’s power characteristics. Measures to reduce the impact of radar-absorbing materials on antenna radiation characteristics may include: radar-absorbing materials margins from the edges of radiating elements, radar-absorbing materials gaps on the inner walls of resonators, and so on.

Garanin S.M., Belov A.S., Polyashov A.M., Bakina L.I., Blokhin A.R. Application of radar-absorbing materials in the design of onboard AFS to reduce radar detectability // Achievements of modern radioelectronics. 2026. V. 80. № 8. P. 8–15. DOI: https://doi.org/10.18127/j20700784-202608-02

1. Krasyuk V.N., Ovodenko A.A., Bestugin A.R., Ryzhikov M.B. Antenny s maloy radiozametnost'yu / Pod nauch. red. V.N. Krasyuka, A.A. Ovodenko. SPb.: Nauka. 2011. (in Russian).
2. Hansen R.C. Relationships between antennas as scatters and as radiators. Proc. IEEE. 1989. V. 77. P. 659–662. (in Russian).
3. Benenson L.S., Fel'd Ya.N. Rasseyaniye elektromagnitnykh voln antennymi: obzor. Radiotekhnika i elektronika. 1988. T. 33. № 2. S. 507–515. (in Russian).
4. Lagar'kov A.N., Pogosyan M.A. Fundamental'n·yye i prikladn·yye problemy Stels-tekhnologiy. Vestnik RAN. 2003. T. 73. № 9. S. 848–852. (in Russian).
5. Krasyuk V.N. Issledovaniye EPR antennykh otsekov letatel'nykh apparatov. Trudy mezhdunar. nauch.-tekhnich. konf. «Povysheniye effektivnosti radioelektronnykh sredstv RV i ASV»: materialy konferentsii, 11-12 aprelya 2000 g. SPb.: VAU, 2000. S. 34–39. (in Russian).
6. Boyko M.A. Obtekateli RLS samoletov novogo pokoleniya. Radiotekhnika. 2002. № 11. S. 12–17. (in Russian).
7. Krasyuk V.N., Ryzhikov M.B. Metody snizheniya radiozametnosti bortovykh antennykh sistem letatel'nykh apparatov. Mnogofunktsional'n·yye radioelektronn·yye kompleksy perspektivnykh letatel'nykh apparatov: sb. dokl. KHK «Leninets». SPb. 2001. S. 90–97. (in Russian).