The relation between corresponding trigonometric functions in two rotating coordinate systems is presented. The transformation formula for a vector in the two rotating spherical coordinate systems is obtained. The sca...The relation between corresponding trigonometric functions in two rotating coordinate systems is presented. The transformation formula for a vector in the two rotating spherical coordinate systems is obtained. The scattering fields for a spherical target irradiated by a plane electromagnetic wave in an arbitrary direction are derived. These fields in a particular case retrogress to those available in the literature. The obtained results have great potential in practical applications.展开更多
The finding of Snell’s law for anomalous reflection enables broad applications of metasurfaces in stealth,communication,radar technology,etc.However,some unavoidable high-order modes are inherently generated due to t...The finding of Snell’s law for anomalous reflection enables broad applications of metasurfaces in stealth,communication,radar technology,etc.However,some unavoidable high-order modes are inherently generated due to the super lattice of this local approach,which thus causes a decrease in efficiency and a limit in the reflected angle.Here,a novel,to our knowledge,low-profile wideband reflective meta-atom shaped like a four-leaf rose is proposed to achieve a phase coverage of full 360°by varying the length of the rose leaf.Then,the genetic algorithm is adopted for the first time to encode and optimize the topology of each meta-atom on the coding metasurface to achieve two-dimensional(2D)anomalous reflection with excellent performances through an inverse design.Numerical results show that our optimized coding metasurfaces achieve a high-efficiency(≥90%)and large-angle(θ≤70°and 0°≤φ≤360°)reflection under normal incidence.For verification,far-field measurement is carried out and experimental results are consistent with the numerical ones.Our work sets up a solid platform for utilizing algorithms,especially in artificial intelligence,in the future for arbitrary 2D anomalous reflection with high efficiency and a large angle.展开更多
基金Project supported by the National Natural Science Foundation of China （Grant No 60171010）, and the Education 0ffice of Shaaxi Province （Grant No 03JK070）.
文摘The relation between corresponding trigonometric functions in two rotating coordinate systems is presented. The transformation formula for a vector in the two rotating spherical coordinate systems is obtained. The scattering fields for a spherical target irradiated by a plane electromagnetic wave in an arbitrary direction are derived. These fields in a particular case retrogress to those available in the literature. The obtained results have great potential in practical applications.
基金National Natural Science Foundation of China(62171459)Innovative Talents Cultivate Program for Technology Innovation Team of Shaanxi Province(2024RSCXTD-08)Key Research and Development Program of Shaanxi Province(2022GD-TSLD-64)。
文摘The finding of Snell’s law for anomalous reflection enables broad applications of metasurfaces in stealth,communication,radar technology,etc.However,some unavoidable high-order modes are inherently generated due to the super lattice of this local approach,which thus causes a decrease in efficiency and a limit in the reflected angle.Here,a novel,to our knowledge,low-profile wideband reflective meta-atom shaped like a four-leaf rose is proposed to achieve a phase coverage of full 360°by varying the length of the rose leaf.Then,the genetic algorithm is adopted for the first time to encode and optimize the topology of each meta-atom on the coding metasurface to achieve two-dimensional(2D)anomalous reflection with excellent performances through an inverse design.Numerical results show that our optimized coding metasurfaces achieve a high-efficiency(≥90%)and large-angle(θ≤70°and 0°≤φ≤360°)reflection under normal incidence.For verification,far-field measurement is carried out and experimental results are consistent with the numerical ones.Our work sets up a solid platform for utilizing algorithms,especially in artificial intelligence,in the future for arbitrary 2D anomalous reflection with high efficiency and a large angle.
