Investigation On Metasurface Based Wideband Virtual Shaping

Whether the eyes or radar,the completion of detection is achieved by receiving the scattering of electromagnetic waves.The virtual shaping technology that can change the detected shape of object to achieve the goal of stealth is the target that people pursued continuously.With the rise of the metasurface,it is possible to realize the scientific stealth and camouflage through the use the metasurface with powerful beam manipulation capability.The manipulation of scattering and transmission by metasurface depends on the phase modulation ability of the structure.In this paper,our goal is to realize the ultra-wideband and multi-frequency phase modulation to improve the versatility of virtual shaping,the unit cell of metasurface and related devices are studied in this paper.The main work of this article is as follows:Arbitrary manipulation of scattering and expanding the working bandwidth are two key tasks in research of virtual shaping.In this paper,we present an ultra-broadband reflective bilayer metasurface to manipulate the scattering of electromagnetic waves based on phase discontinuities resulted from spin-orbit interaction.The polarization conversion efficiency is over 90% in a range covering from 4.9 GHz to 22.8 GHz.Besides,we demonstrate that different virtual shapes can be formed for radar cross section(RCS)reduction.Both simulated and experimental results demonstrated that the significant backward RCS reduction of 9 d B from 5.5 GHz to 22.5 GHz due to the proposed scattering engineering technology.The significant improvement in working bandwidth can be attributed to: the application of the dispersionless phase-shift properties of P-B phase,two-dimensional dispersion management methodology and bilayer metasurface configuration.The proposed design may have the potential applications in stealth and other technologies,and provide a method for broadening the working bandwidth.The realization of the independent phase modulation at multi-wavelength is an important way to improve the bandwidth of the virtual shaping,we proposed a metasurface that can realize independent phase modulations at two microwave wavelengths.The conversion efficiency was above 92% for both wavelengths.In order to verify the performance of the structure,two orbital angular momentum(OAM)with different signs at two microwave bands were generated at near field using the proposed metasurface.In addition,we designed a high-efficiency dual-wavelength deflector that can deflect the transmission waves into same direction for two different frequencies.The numerical results demonstrated that the present structure in this paper offers an effective method to realize high-efficiency transmission and simultaneous frequencyindependent phase modulation.