Ultrabroadband RCS Reduction Design by Exploiting Characteristic Complementary Polarization Conversion Metasurfaces

• Published in: IEEE transactions on antennas and propagation Vol. 70; no. 4; pp. 2904 - 2914
• Main Authors: Deng, Gu-Ying, Zhang, Yun-Hua, He, Si-Yuan, Yan, Hua, Yin, Hong-Cheng, Gao, Huo-Tao, Zhu, Guo-Qiang
• Format: Journal Article
• Language: English
• Published: New York IEEE 01-04-2022; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Algorithms; area ratio; Bandwidth; Bandwidths; Broadband; Broadband communication; complementary polarization conversion metasurface (PCM); complete polarization conversion (CPC) frequency points; Conversion; Design; Frequency conversion; Metasurfaces; Mirrors; Particle swarm optimization; particle swarm optimization (PSO); Phase change materials; Polarization; polarization conversion; radar cross section (RCS) reduction; Radar cross sections; Reduction; Reflectance; Reflection coefficient; Γeff
• ISSN: 0018-926X; 1558-2221
• DOI: 10.1109/TAP.2021.3137228

A new design method for ultrabroadband radar cross section (RCS) reduction by exploiting characteristic complementary polarization conversion metasurfaces (PCMs) is proposed and validated. The proposed method lifts the conventional bandwidth limitation enforced by the performance of a single PCM and expands the RCS reduction bandwidth. A systematic strategy for ultrabroadband RCS reduction design is developed and an effective reflection coefficient amplitude of the composite surface (<inline-formula> <tex-math notation="LaTeX">\Gamma _{ {eff}} </tex-math></inline-formula>) is derived as a new RCS reduction indicator. Based on this indicator, complete polarization conversion (CPC) frequency points of PCM are identified as important characteristics, and PCM pairs with interleaved CPC points, termed as initial PCM (I-PCM) and complementary PCM (C-PCM), are designed to compensate each other for ultrabroadband RCS reduction. A scaling-and-tuning two-step method for designing the C-PCM of a specific I-PCM is developed and validated. To further improve RCS reduction performance, taking the <inline-formula> <tex-math notation="LaTeX">{\Gamma _{ {eff}}} </tex-math></inline-formula> as an indicator, the particle swarm optimization (PSO) algorithm is used to select the optimal I-PCMs, C-PCMs, and their area ratios. Finally, an ultrabroadband RCS reduction surface is designed, fabricated, measured, and validated. It realizes 10-dB monostatic RCS reduction ranging from 7.6 to 26.2 GHz (110.7% relative bandwidth) which exceeds the polarization conversion bandwidth of each individual PCM. Besides, good polarization insensitivity and bistatic RCS reduction performance are also obtained. The proposed method provides a new route for designing broadband RCS reduction surface based on PCMs with unsatisfactory characteristics and greatly alleviates the performance requirement for PCMs.