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Planar Phase Gradient Metasurface Antenna with Low RCS
摘要： A low radar cross section (RCS) planar antenna using phase gradient metasurface is proposed in this paper. The proposed antenna works in the X-band and is fed by a parallel plate waveguide power divider. The designed phase gradient metasurface is coplanar with the feeding structure and couples guided waves in the parallel plate waveguide power divider to radiation waves. According to the generalized reflection law, the proposed metasurface is a frequency scanning antenna and the beam direction can be steered slightly from 16.6° to 13°. The proposed antenna is linearly polarized, and however, the RCS is reduced significantly for arbitrary polarized incident waves. The antenna was simulated, fabricated, and measured. The measurement results confirm well with the simulation results.
关键词： frequency scanning,low profile,Phase gradient metasurface,RCS reduction
更新于2025-09-23 15:23:52
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Radar cross section reduction metasurfaces based on phase gradient and chessboard structure
摘要： In this article, wideband radar cross section (RCS) reduction metasurface is proposed. The unit of the metasurface is consisted of a noncentral symmetry hexagon patch with 2 semi-circular slots at the symmetric corners. As a result, the unit has an anisotropic response for x- and y-polarized wave. The reflection phase is varied with the radius of slots. The range of phase variation is extended by rotation of the unit with 90°. According to the generalized Snell’s Law, 4 different phase gradient supercells with dual polarization characteristics and different gradient directions are obtained. To improve the RCS reduction, chessboard structure is used. By combining these 2 technological approaches, a wideband, polarization insensitive RCS reduction is designed, which can reflect the electromagnetic wave uniformly. Both numerical and measured results show that it enables to realize a 10 dB RCS reduction in a wideband from 8.5 to 13 GHz.
关键词： chessboard structure,metasurface,phase gradient,RCS reduction,phase variation
更新于2025-09-23 15:23:52
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Lightweight Ultra-Wideband RCS Reduction Structure using Double-Layer Metasurfaces
摘要： In this paper, we propose the design of a lightweight RCS reduction structure using double-layer metasurfaces. The structure is composed of two layers of metasurfaces spaced by PMI foams. To extend the bandwidth, two unit structures are firstly designed to operating in two respective bands for circularly polarized (CP) waves, which are then combined to act as the unit structure of the double-layer metasurface. The metasurface is expected to operate in two continuous bands. Nevertheless, due to the couplings between the two unit structures, there is Fano resonance that prohibits merging of the two bands. To solve this problem, we tune the resonant frequency of the bottom unit structure to suppress the Fano resonance and obtain a merged band. The combined unit structure is employed as the element of chessboard configuration, which can reduce RCS by more than 10dB in an ultra-wideband (4.5-16.5GHz). We designed, fabricated and measured a lightweight prototype (the aerial density is 726g/m2). Both the simulation and experiment result verify the design. This work provides an effective method of extending the operation band of RCS reduction without sacrificing the efficiency.
关键词： metasurface,ultra-wideband,Fano resonance,RCS reduction
更新于2025-09-23 15:22:29
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RCS REDUCTION USING A MINIATURIZED UNI-PLANAR ELECTROMAGNETIC BAND GAP STRUCTURE FOR CIRCULARLY POLARIZED MICROSTRIP ANTENNA ARRAY
摘要： In this paper, a new method for radar cross section (RCS) reduction of circularly polarized (CP) microstrip antenna array with small element spacing is proposed. By employing the element rotation technique and loading EBG structures, the in-band and out-of-band RCSs are reduced simultaneously despite the extreme small space between array elements. The simulated results show that the proposed antenna has an average RCS reduction over 10 dB in the X-band for x-polarized and y-polarized incident waves impinging from normal direction compared to the original CP microstrip antenna array, indicating a fractional bandwidth of 40%. The maximum RCS reduction is over 25 dB. Meanwhile, the radiation performance of the proposed antenna array is kept.
关键词： RCS reduction,EBG structures,circularly polarized microstrip antenna array,element rotation technique
更新于2025-09-23 15:21:01
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[IEEE 2019 Photonics & Electromagnetics Research Symposium - Fall (PIERS - Fall) - Xiamen, China (2019.12.17-2019.12.20)] 2019 Photonics & Electromagnetics Research Symposium - Fall (PIERS - Fall) - A Novel Coding Phase Gradient Metasurface for Wideband RCS Reduction
摘要： In this letter, a new design of metasurface based on coding phase gradient metasurface for wideband radar cross section (RCS) reduction is proposed. The unit cell of the metasurface is composed of a Jerusalem structure and a central circular ring. In order to reduce the burden of the computation time and to optimize design procedure, we use the genetic algorithm and nonlinear fitting method to determine the unit cell geometer. By changing and selecting the parameter of each unit, it is found that the reflection phase of the unit can achieve a stable distribution of phase gradient of the cell among the frequency range of 7.5–26 GHz. In our design, both the random coding sequences and gradient phases in the coding elements are combined to manipulate the EM waves. Four kinds of super-cells with different gradient directions are obtained according to the generalized Snell’s Law, serving as the coding element. A coding metasurface composed of 6 × 6 supercells with random arrangement is designed to improve its RCS reduction. By coding four types of linear-phase gradients in a random pattern, reflected wave can be uniformly diffused. Moreover, the manipulation of waves will be more flexible compared with other designs. The simulated results show that a 10 dB RCS reduction is realized over broadband ranging from 7.5 to 26 GHz.
关键词： nonlinear fitting,coding phase gradient,metasurface,genetic algorithm,RCS reduction
更新于2025-09-19 17:13:59
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New Class of RCS-Reduction Metasurfaces Based on Scattering Cancellation Using Array Theory
摘要： A technique to synthesize a new category of Radar Cross Section (RCS)-reduction metasurfaces is presented. The appealing feature of the proposed technique is that by representing the generalized Snell-Descartes’ law of reflection in the form of array factor, it unifies the two most widely studied and well established modern RCS-reduction methods: checkerboard metasurfaces (CMS) and gradient index metasurfaces (GIMS). More importantly, it refines the concepts of both of these metasurfaces and overcomes numerous limitations associated with them. It can synthesize the RCS-reduction metasurfaces which can be placed along with almost any existing metasurface, without replacing the original metasurface that may be designed to serve a specific purpose, to reduce its RCS. The proposed technique is fundamentally based on scattering cancellation, and it is validated using artificial magnetic conductor (AMC) technology for several configurations. Moreover, a phasor representation is developed and implemented for complex configurations to make the synthesis simpler and more insightful. Finally, to display the versatility of the proposed technique, an example of RCS-reduction metasurface has been synthesized and introduced to an existing high-gain metasurface ground plane available in the literature. This paper is confined to the conventional specular direction.
关键词： Scattering cancellation,Array Theory,metasurfaces,RCS reduction,Radar Cross Section,Bragg’s law,Generalized Snell-Descartes’ law,Schelkunoff Polynomial Method,Artificial Magnetic Conductor,Fermat’s principle,Huygens’ principle,Checkerboard
更新于2025-09-11 14:15:04
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A Novel Broadband Bi-Functional Metasurface for Vortex Generation and Simultaneous RCS Reduction
摘要： In this paper, a broadband bi-functional metasurface is presented with capabilities of generating vortex beam for y-polarization and reducing the backward radar cross section (RCS) for x-polarization. With careful optimization, a meta-atom is first designed to control reflection phases for orthogonally polarized wave independently. Then, an integrated phase profile is employed to convert y-polarized spherical wavefront into a vortex spiral one, shaping a vortex high gain beam in the far-field region. By arranging a checkerboard-like phase profile onto the surface for x-polarization, the reflected wave in the backward direction will be canceled, consequently leading to the backward RCS reduction for x-polarization. Combining the above-mentioned cases into a whole, a compact bi-functional metasurface is designed, simulated, physically implemented, and finally measured. In good agreement with the simulated results, the measured ones show that the RCS reduction of 10 dB for x-polarization in comparison with a same-sized metallic plate can be realized over a 67.7 % frequency bandwidth (9–18.2 GHz). Besides, high-efficiency vortex beam conversion effect for y-polarization over a broad range of 11.2–18.2 GHz (47.6%) can also be observed from the measured results.
关键词： vortex beam generator,RCS reduction,Metasurface,bi-functional
更新于2025-09-09 09:28:46
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A NOVEL DUAL-BAND METAMATERIAL ABSORBER AND ITS APPLICATION FOR MICROSTRIP ANTENNA
摘要： In this letter, a novel dual-band metamaterial absorber is presented and analyzed. The absorber is composed of four patches on the top of a thin grounded dielectric substrate which can absorb incident wave at two di?erent frequency bands e?ectively. Then the absorber is loaded on the dual-band microstrip antenna, whose working frequency bands are overlapped with that of the absorber, to reduce the in-band RCS (Radar Cross Section) of antenna. The prototype is simulated, manufactured and measured. Simulated results show that the absorption of the absorber is as high as 98.6% at 4.29 GHz and 99.8% at 6.49 GHz. As to the dual-band antenna loaded with the proposed absorber, its radiation performance is unchanged while the RCS has declined by 8.59 dB at 4.29 GHz and 9.9 dB at 6.49 GHz respectively. There is a good agreement between simulated and measured results, which veri?es that this absorber can be used for in-band RCS reduction of dual-band antenna so as to improve its in-band stealth performance.
关键词： RCS reduction,dual-band metamaterial absorber,microstrip antenna,stealth performance
更新于2025-09-09 09:28:46
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PHASE QUANTIZED METASURFACE SUPERCELLS FOR WAVE MANIPULATION AND RCS REDUCTION
摘要： Recently, the introduction of surface phase in Snell’s law and Huygens’ phenomena leads to ultrathin phased surfaces which can tailor the transmission and scattering of the incident wavefront in many ways. In this article, a remodeled Jerusalem cross used as the meta-element whose geometrical parameters are varied to obtain 360? phase variation and a 3-bit quantization is presented to design phase coded surfaces to manipulate (focusing and splitting) normally incident beam. Further, two 3-bit phase quantized supercells of approximately 2λ length and width are proposed and simulated (3 × 3 matrix arrangement) to test and compare the scattering properties with traditional chessboard type supercell. Obtained simulated results show di?used re?ections for both the models and reduced intensity of four corner lobes in comparison to chessboard supercells (at θ = 30? and φ = 45?). Experimentally recorded monostatic RCS of model-2 prototype has a close agreement with the simulated results and more than 10 dBsm RCS reduction observed from 9 GHz–11 GHz.
关键词： wave manipulation,metasurface,RCS reduction,phase quantization,Jerusalem cross
更新于2025-09-04 15:30:14
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[Institution of Engineering and Technology 12th European Conference on Antennas and Propagation (EuCAP 2018) - London, UK (9-13 April 2018)] 12th European Conference on Antennas and Propagation (EuCAP 2018) - Uneven-layered Metamaterial Tile for Ultra-wideband RCS Reduction
摘要： In this paper, a novel uneven-layered metamaterial tile is proposed for ultra-wideband radar cross section (RCS) reduction. The metamaterial tile is composed of two kinds of square ring unit cells with different layer thickness. The reflection phase difference of 180° (±37°) between two unit cells covers an ultra-wide frequency range. The metamaterial tile can achieve -10 dB RCS reduction from 6.2 GHz to 25.7 GHz with the ratio bandwidth of 4.15:1 at normal incidence. The measured and simulated results are in good agreement and validate the proposed uneven-layered metamaterial tile can greatly expanding the bandwidth for RCS reduction.
关键词： RCS reduction,Metamaterial tile,Ultra-wideband
更新于2025-09-04 15:30:14