Conformal Frequency Selective Surfaces in Radome Design: A Mini Review

Öz

In aerospace engineering, radomes play an important role in protecting antenna systems from external interference and minimizing air resistance during flight. However, traditional radomes often fall short of providing the electromagnetic filtering and stealth capabilities important for modern aircraft applications. Conformal Frequency Selective Surfaces (FSS) radomes represent an evolutionary step beyond their conventional counterparts. These structures not only continue to protect antenna structures from environmental adversities, but also adapt seamlessly to non-planar surfaces. This adaptation is not only functional but also covers aerodynamic and aesthetic considerations, improving stealth capabilities and multi-band frequency operability, which are key factors for state-of-the-art communications and radar systems. However, design and implementation of conformal FSS radomes have some challenges. Considering that one of the authors has focused on such challenges for new generation air platforms, this study examines the contemporary advancements in conformal FSS radome technology, highlighting the latest research and breakthroughs. It covers latest findings on cutting-edge materials, design methodologies, simulation techniques for performance prediction, and the practical applications and advantages of these radomes. Building on a theoretical foundation of FSS and radome integration, the article discusses material and design innovations, simulation challenges, and practical implementations. It is hoped that this review will act as a bridge for knowledge sharing and a stimulant for continued research within the domain of conformal FSS radome technology

Anahtar Kelimeler

• Conformal Frequency Selective Surfaces (FSS)
• Radomes
• Aerospace Engineering

Radom Tasarımında Konformal Frekans Seçi̇ci̇ Yüzeyler Üzerine Kısa bir Değerlendirme

Öz

Havacılık mühendisliğinde, radomlar anten sistemlerini dış müdahalelerden koruma ve uçuş sırasında hava direncini en aza indirme konusunda önemli bir rol oynar. Ancak, geleneksel radomlar modern uçak uygulamaları için önemli olan elektromanyetik filtreleme ve gizlilik yeteneklerini sağlama konusunda genellikle yetersiz kalır. Konformal frekans seçici yüzey (FSY) radomları, geleneksel muadillerinin ötesinde evrimsel bir adımı temsil eder. Bu yapılar, sadece anten yapılarını çevresel olumsuzluklardan korumakla kalmaz, aynı zamanda düzlemsel olmayan yüzeylere sorunsuz bir şekilde uyum sağlar. Bu uyum, sadece işlevsel değil, aynı zamanda aerodinamik ve estetik kaygıları da kapsar, gizlilik yeteneklerini ve çok bantlı frekans çalışabilirliğini artırır; bu da en son iletişim ve radar sistemleri için anahtar faktörlerdir. Konformal FSY radomların tasarım ve gerçeklenmesinde çok ciddi zorluklar vardır. Yazarlardan birinin yeni jenerasyon hava platofrmları için bu tip zorluklara odaklandığı dikkate alınarak bu çalışma, konformal FSY radom teknolojisindeki çağdaş gelişmeleri incelemekte, en son araştırmaları ve atılımları vurgulamaktadır. En son malzemeler, tasarım metodolojileri, performans tahmini için simülasyon teknikleri ve bu radomların pratik uygulamaları ve avantajları ele alınmaktadır. FSY ve radom entegrasyonunun teorik temeli üzerine inşa edilen makale, malzeme ve tasarım yeniliklerini, simülasyon zorluklarını ve pratik uygulamaları tartışmaktadır. Bu incelemenin, konformal FSY radom teknolojisi alanında bilgi paylaşımı için bir köprü ve sürekli araştırmalar için bir teşvik olması umulmaktadır

Anahtar Kelimeler

• Konformal Frekans Seçici Yüzeyler (FSY)
• Radom
• Havacılık Mühendisliği

Kaynakça

1. [1] D. J. Kozakoff, Analysis of radome-enclosed antennas, 2nd ed., Norwood, MA: Artech House, 2010, pp. 3-4.
2. [2] B. Gao, S. Huang, Z. Ren, Y. Chen and X. Wang, "Design and Verification of an Integrated Free-Standing Thick-Screen FSS Radome," in IEEE Antennas and Wireless Propagation Letters, vol. 17, no. 9, pp. 1630-1634, Sept. 2018, doi: 10.1109/LAWP.2018.2859232.
3. [3] M. Okramcha and M. R. Tripathy, "Designing and Performance Analysis of Low Insertion Loss with Polarization-Insensitive FSS-antennaradome system for Airborne Applications," 2023 10th International Conference on Signal Processing and Integrated Networks (SPIN), Noida, India, 2023, pp. 323-328, doi: 10.1109/SPIN57001.2023.10117350.
4. [4] B. Munk, Frequency selective surfaces: theory and design. New York, NY, USA: Wiley, 2000, pp. 3-4
5. [5] Q. Chen, and Y. Fu, "A planar stealthy antenna radome using absorptive frequency selective surface, " Microw. Opt. Techn. Let., vol.56, no.8, pp. 1788-1792, 2014. https://doi.org/10.1002/mop.28442.
6. [6] M. Okramcha and M. R. Tripathy, "Designing and Performance Analysis of Low Insertion Loss with Polarization-Insensitive FSS-antennaradome system for Airborne Applications," 2023 10th International Conference on Signal Processing and Integrated Networks (SPIN), Noida, India, 2023, pp. 323-328, doi: 10.1109/SPIN57001.2023.10117350.
7. [7] Anwar, Rana Sadaf, Lingfeng Mao, and Huansheng Ning. 2018. "Frequency Selective Surfaces: A Review" Applied Sciences 8, no. 9: 1689. https://doi.org/10.3390/app8091689.
8. [8] Yang, F.; Rahmat-Samii, Y. Electromagnetic Band Gap Structures in Antenna Engineering; Cambridge University Press: Cambridge, UK, 2009.

9. [9] Yogesh Solunke, Ashwin Kothari, " An ultrathin, low-RCS, dual-bandpass novel fractal-FSS for planar/conformal C&X bands applications”, AEU - International Journal of Electronics and Communications, Volume 175,2024,155073, ISSN 1434-8411, https://doi.org/10.1016/j.aeue.2023.155073.
10. [10] M. Okramcha and M. R. Tripathy, "Designing and Performance Analysis of Low Insertion Loss with Polarization-Insensitive FSSantenna-radome system for Airborne Applications," 2023 10th International Conference on Signal Processing and Integrated Networks (SPIN), Noida, India, 2023, pp. 323- 328, doi: 10.1109/SPIN57001.2023.10117350.
11. [11] Y. Xu, S. Zhang, S. Chen, and H. Zhao, "A Band Pass Conformal Frequency Selective Surface Radome," 2021 IEEE 6th International Conference on Signal and Image Processing (ICSIP), Nanjing, China, 2021, pp. 876-880, doi: 10.1109/ICSIP52628.2021.9688798.
12. [12] B. Gao, S. Huang, Z. Ren, Y. Chen, and X. Wang, "Design and Verification of an Integrated Free-Standing Thick-Screen FSS Radome," in IEEE Antennas and Wireless Propagation Letters, vol. 17, no. 9, pp. 1630-1634, Sept. 2018, doi: 10.1109/LAWP.2018.2859232.
13. [13] Y. Zhang, T. Dong, D. Sun, Y. Wang, and S. Lü, "Electromagnetic Analysis of a JigsawShaped FSS for Conformal Application," 2020 50th European Microwave Conference (EuMC), Utrecht, Netherlands, 2021, pp. 768-771, doi: 10.23919/EuMC48046.2021.9338094.
14. [14] H. Zhou et al., "Filter-Antenna Consisting of Conical FSS Radome and Monopole Antenna," in IEEE Transactions on Antennas and Propagation, vol. 60, no. 6, pp. 3040-3045, June 2012, doi: 10.1109/TAP.2012.2194648.
15. [15] T. Tian et al., "Flexible and Reconfigurable Frequency Selective Surface with Wide Angular Stability Fabricated With Additive Manufacturing Procedure," in IEEE Antennas and Wireless Propagation Letters, vol. 19, no. 12, pp. 2428-2432, Dec. 2020, doi: 10.1109/LAWP.2020.3034944.
16. [16] W. Y. Yong et al., "Flexible Convoluted Ring Shaped FSS for X-Band Screening Application," in IEEE Access, vol. 6, pp. 11657-11665, 2018, doi: 10.1109/ACCESS.2018.2804091.
17. [17] W. Li, Y. Lan, H. Wang, and Y. Xu, "Microwave Polarizer Based on Complementary Split Ring Resonators Frequency-Selective Surface for Conformal Application," in IEEE Access, vol. 9, pp. 111383-111389, 2021, doi: 10.1109/ACCESS.2021.3102942.
18. [18] P. -S. Wei, C. -N. Chiu, C. -C. Chou and T. - L. Wu, "Miniaturized Dual-Band FSS Suitable for Curved Surface Application," in IEEE Antennas and Wireless Propagation Letters, vol. 19, no. 12, pp. 2265-2269, Dec. 2020, doi: 10.1109/LAWP.2020.3029820.
19. [19] S. Dhegaya and L. Tanwar, "Stable Gain with Frequency Selective Surface in Planar and Conformal Structure: For Radome Application," 2022 Trends in Electrical, Electronics, Computer Engineering Conference (TEECCON), Bengaluru, India, 2022, pp. 97-102, doi: 10.1109/TEECCON54414.2022.9854836.
20. [20] X. Sheng, H. Wang, N. Liu and K. Wang, "A Conformal Miniaturized Bandpass FrequencySelective Surface with Stable Frequency Response for Radome Applications," in IEEE Transactions on Antennas and Propagation, vol. 72, no. 3, pp. 2423-2433, March 2024, doi: 10.1109/TAP.2024.334967.
21. [21] Ankush Kapoor, Ranjan Mishra, Pradeep Kumar, Frequency selective surfaces as spatial filters: Fundamentals, analysis and applications, Alexandria Engineering Journal, Volume 61, Issue 6, 2022, Pages 4263-4293, ISSN 1110- 0168, https://doi.org/10.1016/j.aej.2021.09.046.
22. [22] Fernández Álvarez, Humberto & Cadman, Darren & Goulas, Athanasios & Gómez, M. &
23. [23]Engstrom, Daniel & Vardaxoglou, John Yiannis & Zhang, Shiyu. (2021). 3D conformal bandpass millimeter-wave frequency selective surface with improved fields of view. Scientific Reports. 11. 10.1038/s41598-021-91218-y.
24. [24] A. Gouda, R. K. Mishra and S. Ghosh, "An FSS-based Conformal Band-stop Filter Design for Planar and Non-planar Surfaces," 2022 IEEE Microwaves, Antennas, and Propagation Conference (MAPCON), Bangalore, India, 2022, pp. 506-510, doi:10.1109/MAPCON56011.2022.10047603.
25. [25] Anwar, R.S.; Mao, L.; Ning, H. Frequency Selective Surfaces: A Review. Appl. Sci. 2018, 8, 1689. https://doi.org/10.3390/app8091689.
26. [26] C. L. Valle, G. T. Carranza and R. C. Rumpf, "Conformal Frequency Selective Surfaces for Arbitrary Curvature," in IEEE Transactions on Antennas and Propagation, vol. 71, no. 1, pp. 612-620, Jan. 2023, doi: 10.1109/TAP.2022.3216960.
27. [27] P. Gurrala, S. Oren, P. Liu, J. Song and L. Dong, "Fully Conformal Square-Patch Frequency-Selective Surface Toward Wearable Electromagnetic Shielding," in IEEE Antennas and Wireless Propagation Letters, vol. 16, pp. 2602-2605, 2017, doi: 10.1109/LAWP.2017.2735196.
28. [28] H. Minjie, "High-Precision Modeling for Arbitrary Curved Frequency Selective Structures Based on Perfect Mapping Between Thick Surface and Its Minimum Distortion FlatUnfolding Solution," in IEEE Access, vol. 12, pp. 30533-30543, 2024, doi: 10.1109/ACCESS.2024.3365541.
29. [29] Y. Fu, F. Ding, J. Jin, H. Cheng, Y. Yang, X. Zhou, Y. Dai, and H. Yang, "Conformal frequency selective rasorber in S, C, X-band with low backward scattering," Opt. Express 32, 16879- 16890 (2024).
30. [30] M. M. Zargar, A. Rajput, K. Saurav and S. K. Koul, "Single-Layered Flexible Dual Transmissive Rasorbers with Dual/Triple Absorption Bands for Conformal Applications," in IEEE Access, vol. 9, pp. 150426-150442, 2021, doi: 10.1109/ACCESS.2021.3126197.
31. [31] Thulasiraman, Jayanandan & Alex, Zachariah. (2024). Ultrathin and conformal frequency selective surfaces bandpass filter to eliminate the 5G bands on radio altimeters. Microwave and Optical Technology Letters. 66. 10.1002/mop.34001.