scholarly journals Design of a Low Scattering Metasurface for Stealth Applications

Materials ◽  
2019 ◽  
Vol 12 (18) ◽  
pp. 3031 ◽  
Author(s):  
Tayyab Ali Khan ◽  
Jianxing Li ◽  
Juan Chen ◽  
Muhammad Usman Raza ◽  
Anxue Zhang
Keyword(s):  
Cross Section ◽  
Phase Difference ◽  
Metallic Plate ◽  
Frequency Range ◽  
Magnetic Conductor ◽  
Relative Bandwidth ◽  
Good Accordance ◽  
Unit Cells ◽  
Effective Phase ◽  
Phase Reflection

The design of a metasurface with low radar cross section (RCS) property is presented in this paper. The low scattering of the metasurface is achieved by applying the artificial magnetic conductor (AMC) unit cells in three different configurations. Two different AMC unit cells with an effective phase difference of 180 ± 37° are first designed to analyze the out of phase reflection in a wideband frequency range from 5.9 to 12.2 GHz. Then, the unit cells are placed in a chessboard-like configuration, newly constructed rotated rectangular-shaped configuration, and optimized configuration to study and compare the RCS reduction performance. All designs of the metasurface with different configurations show obvious RCS reduction as compared with the metallic plate of the same size. However, the relative bandwidth of the optimized metasurface is larger than the chessboard-like configuration and rotated rectangular-shaped configuration. To certify the results of the simulations, the metasurface with the optimized configuration is fabricated further to measure the RCS reduction bandwidth. The measured results are in good accordance with the simulated results. Therefore, the proposed metasurface can be a good option for applications where low RCS is desirable.

scholarly journals Wideband RCS Reduction Using Coding Diffusion Metasurface

Materials ◽  
2019 ◽  
Vol 12 (17) ◽  
pp. 2708 ◽  
Author(s):  
Ali ◽  
Li ◽  
Khan ◽  
Yi ◽  
Chen
Keyword(s):  
Cross Section ◽  
Phase Difference ◽  
Frequency Band ◽  
Optimization Algorithm ◽  
Radar Cross Section ◽  
Reduction Technique ◽  
Metallic Plate ◽  
Random Optimization ◽  
Unit Cells ◽  
Working Frequency

This paper presents a radar cross-section (RCS) reduction technique by using the coding diffusion metasurface, which is optimised through a random optimization algorithm. The design consists of two unit cells, which are elements ‘1’ and ‘0’. The reflection phase between the two-unit cells has a 180° ± 37° phase difference. It has a working frequency band from 8.6 GHz to 22.5 GHz, with more than 9 dB RCS reduction. The monostatic RCS reduction has a wider bandwidth of coding diffusion metasurface as compared to the traditional chessboard metasurface. In addition, the bistatic performance of the designed metasurfaces is observed at 15.4 GHz, which shows obvious RCS reduction when compared to a metallic plate of the same size. The simulated and measured result shows the proficiency of the designed metasurface.

scholarly journals Gain-Enhanced Metamaterial Absorber-Loaded Monopole Antenna for Reduced Radar Cross-Section and Back Radiation

Materials ◽  
2020 ◽  
Vol 13 (5) ◽  
pp. 1247
Author(s):  
Heijun Jeong ◽  
Yeonju Kim ◽  
Manos M. Tentzeris ◽  
Sungjoon Lim
Keyword(s):  
Cross Section ◽  
Radar Cross Section ◽  
Metamaterial Absorber ◽  
Monopole Antenna ◽  
Magnetic Conductor ◽  
Low Profile ◽  
Before And After ◽  
Unit Cells ◽  
Lumped Elements ◽  
Peak Gain

This paper proposes a gain-enhanced metamaterial (MM) absorber-loaded monopole antenna that reduces both radar cross-section and back radiation. To demonstrate the proposed idea, we designed a wire monopole antenna and an MM absorber. The MM absorber comprised lumped elements of subwavelength unit cells and achieved 90% absorbance bandwidth from 2.42–2.65 GHz. For low-profile configurations, the MM absorber was loaded parallel to and 10 mm from the monopole antenna, corresponding to 0.09 λ0 at 2.7 GHz. The monopole antenna resonated at 2.7 GHz with a 3.71 dBi peak gain and 2.65 GHz and 6.46 dBi peak gain, before and after loading the MM absorber, respectively. Therefore, including the MM absorber increased peak gain by 2.7 dB and reduced back radiation by 15 dB. The proposed antenna radar cross-section was reduced by 2 dB compared with a monopole antenna with an artificial magnetic conductor.

scholarly journals A 2-Bit Pancharatnam-Berry Coding Metasurface For Ultra-Wideband And Polarization-Insensitive RCS Reduction

2021 ◽  
Author(s):  
Baoqin Lin ◽  
Wenzhun Huang ◽  
Yong-sheng Yang ◽  
Lin-tao Lv ◽  
Jianxin Guo ◽  
...  
Keyword(s):  
Reflection Coefficient ◽  
Cross Section ◽  
Ultra Wideband ◽  
Polarization Conversion ◽  
Metallic Plate ◽  
Excellent Performance ◽  
Unit Structure ◽  
Relative Bandwidth ◽  
Simulation And Experiment ◽  
Polarization Insensitive

Abstract Because Pancharatnam-Berry (PB) geometrical phase can only be generated in the co-polarized reflection coefficient under circular polarized (CP) incidence for a reflective metasurface, designing a reflective PB coding metasurface must be based on an appropriate polarization conversion metasurface (PCM), which can realize CP-maintaining reflection. In this work, to design a reflective 2-dit PB coding metasurface for radar cross section (RCS) reduction, an ultra-wideband PCM is proposed at first, the simulated results show that the PCM can realize ultra-wideband CP-maintaining reflection from 8.6 to 35.9 GHz; moreover, PB phase will be generated in its co-polarized reflection coefficient by rotating its unit structure. Thus based on the PCM, an ultra-wideband reflective 2-dit PB coding metasurface is constructed successfully. The simulation and experiment results show that the coding metasurface has excellent performance in RCS reduction under arbitrary polarized incidences, compared with a pure metallic plate with the same size, its RCS can be reduced more than 10dB in the frequency band 8.2-35.2GHz with a relative bandwidth of 124.4%.

scholarly journals An Ultrawideband Polarization-Insensitive Diffusion Metasurface Using Period Changed Unit Cell for RCS Reduction

Materials ◽  
2021 ◽  
Vol 14 (17) ◽  
pp. 5053
Author(s):  
Jianzhong Chen ◽  
Chengwei Zhang ◽  
Yutong Zhao ◽  
Lei Lin ◽  
Liang Li ◽  
...  
Keyword(s):  
Cross Section ◽  
Phase Difference ◽  
Rotational Symmetry ◽  
Radar Cross Section ◽  
Unit Cell ◽  
Operating Frequency ◽  
Reflection Amplitude ◽  
Good Consistency ◽  
Unit Cells ◽  
Polarization Insensitive

A polarization-insensitive diffusion metasurface using a period-changed unit cell is presented for reducing the radar cross-section (RCS) of metallic objects in ultrawideband. Two metallic Minkowski loops are proposed as coding elements, different from traditional designs. The “0” element is constructed by period-changed unit cells to achieve a 180 ± 30° phase difference with the same reflection amplitude of nearly −0.9 dB in an ultrawideband from 7.1 to 29.2 GHz. Multilayer geometry with a thickness of 4.5 mm (about 0.105λ0 at the lowest operating frequency) and rotational symmetry loops are used to realize the ultrawideband characteristic and polarization-insensitive behavior. For verification, a polarization-insensitive diffusion metasurface is designed, fabricated, and measured. The simulated and measured results of the diffusion metasurface are in good consistency and the results both show that the metasurface enables a 10 dB backscattering reduction over an amazing ultrawideband ranging from 7.1 to 29.2 GHz (BW of 122%).

Broadband radar cross-section reduction using polarization conversion metasurface

2018 ◽  
Vol 10 (2) ◽  
pp. 197-206 ◽  
Author(s):  
Qi Zheng ◽  
Chenjiang Guo ◽  
Haixiong Li ◽  
Jun Ding
Keyword(s):  
Cross Section ◽  
High Efficiency ◽  
Normal Incidence ◽  
Radar Cross Section ◽  
Conversion Ratio ◽  
Polarization Conversion ◽  
Metallic Plate ◽  
Relative Bandwidth ◽  
Plasmon Resonances ◽  
The Relationship

AbstractA wideband and high-efficiency polarization conversion metasurface (PCM) is proposed and applied to reduce radar cross section (RCS). The proposed PCM unit is composed of two oblique asymmetry triangle split rings, which generate multiple plasmon resonances. Simulated and measured results demonstrate that it achieves polarization conversion over 90% from 9.24 to 17.64 GHz. Besides square checkerboard, the proposed PCM units and mirror units are arranged in triangle checkerboard. The mechanisms of both checkerboard PCMs are analyzed based on standard array theory, including the relationship between RCS reduction value and polarization conversion ratio value. The derived formulas provide a guideline to design checkerboard structure based on PCM. Simulated results demonstrate that both checkerboard PCMs achieve over 62% relative bandwidth of 10 dB RCS reduction under normal incidence with respect to the equal-sized metallic plate, which also means that the triangle one could be an alternative solution to reduce RCS. To verify the analyzed and simulated results, the fabricated sample and measured results of both checkerboard PCMs are presented. Good agreements are achieved between measurements, simulations and numerical analysis.

Coupled Piezoelectric Phononic Crystal for Adaptive Broadband Wave Attenuation by Destructive Interference

2020 ◽  
Vol 87 (9) ◽  
Author(s):  
Jiawen Xu ◽  
Xin Zhang ◽  
Ruqiang Yan
Keyword(s):  
Phase Difference ◽  
Wave Attenuation ◽  
Phononic Crystal ◽  
Low Frequency ◽  
Crystal Plate ◽  
Destructive Interference ◽  
Negative Capacitance ◽  
Frequency Range ◽  
Frequency Wave ◽  
Unit Cells

Abstract In this paper, we report a piezoelectric phononic crystal plate featuring broadband wave attenuation. In the piezoelectric phononic crystal system, the transmitted elastic wave is attenuated owing to destructive interference by taking advantages of phase difference. The proposed concept is applied to a piezoelectric phononic crystal plate synthesized by functional dual-lane units that yields phase difference. Whereas, the piezoelectric unit-cells are connected negative capacitance shunt circuits individually. Our analysis shows that the coupled phononic crystal has a strong broadband low-frequency wave attenuation capability. The bandwidth of 10 dB wave attenuation is broadened by 34 times in the vicinity of 5 kHz comparing to that of a local resonance metamaterial under the same mechanical configuration. Moreover, the frequency range of wave attenuation of the proposed system can be online adjusted through the modification of the external shunt circuits.

scholarly journals Broadband Adaptive RCS Computation through Characteristic Basis Function Method

2014 ◽  
Vol 2014 ◽  
pp. 1-5
Author(s):  
Guohua Wang ◽  
Yufa Sun
Keyword(s):  
Cross Section ◽  
Basis Function ◽  
Function Method ◽  
High Accuracy ◽  
Wide Frequency Range ◽  
Singular Value ◽  
Basis Functions ◽  
Frequency Range ◽  
Arbitrary Frequency ◽  
Value Decomposition

A broadband radar cross section (RCS) calculation approach is proposed based on the characteristic basis function method (CBFM). In the proposed approach, the desired arbitrary frequency band is adaptively divided into multiple subband in consideration of the characteristic basis functions (CBFs) number, which can reduce the universal characteristic basis functions (UCBFs) numbers after singular value decomposition (SVD) procedure at lower subfrequency band. Then, the desired RCS data can be obtained by splicing the RCS data in each subfrequency band. Numerical results demonstrate that the proposed method achieve a high accuracy and efficiency over a wide frequency range.

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