Radar Absorbing Materials

Abstract

In this study, elastomer-based radar absorber materials (H-RGCs) prepared using nano-sized conductive fillers present a comparative experimental methodology to characterize the cross-sectional radar field (RSA) reduction efficiency and performance in the 6-17 GHz band with 3°steps from 0 to 360º. The reference material (M-REM) used in the comparison is designed to reduce the radar cross-section area of military land vehicles (tank, truck, ship, etc.) and is currently commercially available. A six-layer, symmetrical and thin radar absorber material with reflective surfaces in both directions, exhibiting excellent broadband properties, was designed and manufactured. Carbon black and graphene nanoplatelets were used to produce the required rubber composite to form the reflective surface and hybrid layer. Similar results were obtained in the measurements made for both materials, and it was seen that the produced material could be used in systems such as ships and military land vehicles for RSA reduction. The results showed that both material types could achieve a reduction of 20 dBsm. The best RSA values, regardless of frequency, are obtained between 24-72º for M-REM, while for H-RGC, it is in the range of 21-72º. It was observed that the RSA values improved as the frequency bandwidth increased for both materials. In the tests performed at 12 GHz frequency for M-REM, the lowest absorption value was measured at 72°, 42.6743 dBsm, and the lowest absorption value for H-RGC was 42.9219 dBsm. The similarity and match between the measurement results of the H-RGC materials produced as an alternative to the commercially used and proven M-REM showed the validity of our design and gave promising results for future studies.

Keywords

• Radar Absorbing Material
• Radar Cross Section Reduction
• Elastomer
• Conductivity Properties
• Functional Composites

Nanoyapılı iletken dolgulu polimer ile geniş bant çok katmanlı radar soğurucu malzemelerin geliştirilmesi

Öz

Bu çalışma, nano boyutlu iletken dolgu malzemeleri kullanılarak hazırlanan elastomer esaslı radar soğurucu malzemelerin (H-RGC), 0-360º arasında 3°’lik adımlar ile 6-17 GHz frekans bant aralığındaki radar kesit alanı (RSA) azaltma verimliliği ve performansını karakterize etmek için karşılaştırmalı deneysel metodoloji sunmaktafdır. Karşılaştırma kapsamında kullanılan referans malzeme (M-REM) askeri kara araçlarının (tank, kamyon, gemi vb) radar kesit alanını azaltmak için tasarlanmış olup hali hazırda ticari olarak satılmaktadır. Mükemmel geniş bant özellikleri sergileyen, her iki yönde yansıtıcı yüzey içeren altı katmanlı, simetrik ve ince radar soğurucu malzeme tasarlanmış ve üretilmiştir. Karbon siyahı ve grafen nanoplateletler, sırasıyla yansıtıcı yüzey ve hibrit katmanı oluşturmak için gerekli kauçuk kompozit üretmek için kullanıldı. Her iki malzeme için yapılan ölçümlerde benzer sonuçlar elde edilmiş olup üretilen malzemenin gemi, askeri kara araçları gibi sistemlerde RSA azaltımında kullanılabileceğini görülmüştür. Sonuçlar, her iki malzeme tipinin de 20 dBsm değerinde bir azaltım sağlayabildiğini göstermiştir. M-REM için frekanstan bağımsız olarak en iyi RSA değerleri 24-72º ’ler arasında elde edilmişken, H-RGC için 21-72º aralığındadır. Her iki malzeme için frekans bant genişliği artıkça RSA değerlerinin de iyileştiği görülmüştür. M-REM için 12 GHz frekans da yapılan testlerde en düşük soğurma değeri 72° de, 42,6743 dBsm , H-RGC için en düşük soğurma değeri olarak 42,9219 dBsm ölçülmüştür. Ticari olarak kullanılan ve geçerliliğini kanıtlamış M-REM’e alternatif olarak ürettilen H-RGC malzemelerinin ölçüm sonuçları arasındaki benzerlik ve eşleşme, tasarımımızın geçerliliğini gösstermiş ve ileri de yapılacak çalışmalar için umut verici sonuçlar elde edilmiştir.

Anahtar Kelimeler

• Radar Soğurma Malzemesi
• Radar Kesit Alanı Azaltımı
• Elastomer
• İletkenlik Özellikleri
• Foksiyonel Kompozitler

References

1. Li Z.W., Yang Z.H., Kong L.B. (2010). Ultrabroad bandwidth of single-layer electromagnetic attenuation composites with flaky fillers. Applied Physics Letters, 90(9), 092507. https://doi.org/10.1063/1.3340460
2. Park K.Y., Lee S.E., Kim C.G., Han J.H. (2006). Fabrication and electromagnetic characteristics of electromagnetic wave absorbing sandwich structures. Composite Science and Technology 66(3-4), 576–84. https://doi.org/10.1016/j.compscitech.2005.05.034
3. Ren W, Nie Y, Xiong X, Zhang C, Zhou Y, Gong R. (2012). Enhancing and broadening absorption properties of frequency selective surfaces absorbers using FeCoBbased thin film. Journal of Applied Physics, 111(7), 07E703. https://doi.org/10.1063/1.3670980
4. Liu Q, Zhang D, Fan T. (2008). Electromagnetic wave absorption properties of porous carbon/Co nanocomposites. Applied Physics Letters, 93(1), 013110. https://doi.org/10.1063/1.2957035
5. Xu H., Bie S., Xu Y., Yuan W., Chen Q., Jiang J. (2016). Broad bandwidth of thin composite radar absorbing structures embedded with frequency selective surfaces. Composites Part A-applied Science and Manufacturing, 80, 111-117. https://doi.org/10.1016/j.compositesa.2015.10.019
6. Knott E., Shaeffer, J, Tuley, M. (2004). Radar Cross Section. SciTech Publishing Inc., Raleigh.
7. Badawy M.M, Zainud-Deen S.H.,Malhat H.A. (2020). Radar-Cross-Section Reduction Using Polarization Conversion Metasurface. 37th National Radio Science Conference (NRSC), 2020, pp. 66-73. doi: 10.1109/NRSC49500.2020.9235105.
8. Zhang L., Dong T. (2017). Low RCS and high-gain CP microstrip antenna using SA-MS. Electronics Letters, 53(6), 375-376. https://doi.org/10.1049/el.2016.4654

9. Kazantsev Y.N., Lopatin A., Kazantseva N., Shatrov, A.D., Mal’tsev V., Vilčáková J., Sáha P. (2010). Broadening of Operating Frequency Band of Magnetic-Type Radio Absorbers by FSS Incorporation. IEEE Transactions on Antennas and Propagation, 58(4), 1227-1235. DOI: 10.1109/TAP.2010.2041316
10. Shang Y., Shen Z., Xiao S. (2013). On the Design of Single-Layer Circuit Analog Absorber Using Double-Square-Loop Array. IEEE Transactions on Antennas and Propagation, 61(12), 6022-6029. DOI: 10.1109/TAP.2013.2280836
11. Franchitto M., Faez R., Orlando A.J.F., Rezende M.C., Martin I.M. (2001). Electromagnetic behavior of radar absorbing materials based on conducting polymers. Proceedings of the 2001 SBMO/IEEE MTT-S International Microwave and Optoelectronics Conference. (Cat. No.01TH8568), 2001, pp. 137-140 vol.1, doi: 10.1109/SBMOMO.2001.1008736.
12. Folgueras L.C., Rezende M.C. (2008). Multilayer radar absorbing material processing by using polymeric nonwoven and conducting polymer. Materials Research-ibero-american Journal of Materials, 11(3), 245-249. https://doi.org/10.1590/S1516-14392008000300003
13. Pratap V., Soni A.K., Siddiqui A.M., Abbas S.M., Katiyar R., Prasad N.E. (2020). Dielectric and Radar-Absorbing Properties of Exfoliated Graphite Dispersed Epoxy Composites. Journal of Electronic Materials, 49, 3972–3981. https://doi.org/10.1007/s11664-020-08118-6
14. Vinoy K., Jha R. (2011). Radar Absorbing Materials: From Theory to Design and Characterization. Boston: Kluwer Academic Publishers.
15. Silva V.A., Folgueras L.C., Cândido G.M., Paula A., Rezende M.C., Costa M.L. (2013). Nanostructured Composites Based on Carbon Nanotubes and Epoxy Resin for Use as Radar Absorbing Materials. Materials Research-ibero-american Journal of Materials, 16(6), 1299-1308. DOI: 10.1590/S1516-14392013005000146
16. Kunrath K., Kerche E.F., Rezende M.C., Amico S. (2019). Mechanical, electrical, and electromagnetic properties of hybrid graphene/glass fiber/epoxy composite. Polymers and Polymer Composites, 27(5), 262 - 267. https://doi.org/10.1177/0967391119828559
17. Sasria N., Ardhyananta H., Fajarin R., Widyastuti R. (2017). Synthesis and Characterization of BaFe12O19/Poly(aniline, pyrrole, ethylene terephthalate) Composites Coatings as Radar Absorbing Material (RAM). Journal of Physics: Conference Series, 877, 012057.
18. Avloni, D.J., Henn D.A. (2007). Development of New Conductive and Microwave-Lossy Materials Involving Conducting Polymer Coatings.
19. Dedov A.V., Nazarov V.G.(2016). Multilayer Radar Absorbing Non-Woven Material. Radiophysics and Quantum Electronics, 59(1), 43–47. https://doi.org/10.1007/s11141-016-9674-x
20. Wong T.C.P., Chambers B., Anderson A.P., Wright P.V. (1995). Characterisation of conducting polymer-loaded composite materials at oblique incidence and their application in radar absorbers. Ninth International Conference on Antennas and Propagation, ICAP '95 (Conf. Publ. No. 407), 1995, pp. 441-444 vol.1, doi: 10.1049/cp:19950346.
21. Nalwa H.S. (1997). Conductive Polymers: Synthesis and Electrical Properties in Handbook of Organic Conductive Molecules and Polymers, v. 2, John Wiley & Sons, New York.