Research And Design Of High Gain Beam Steering Antenna On LEO Satellite

In recent years,low-orbit space has gradually become the focus of global space development.Due to the limitation of the spatial position of the orbit,the satellite has certain requirements on the communication coverage and communication quality.The highly integrated antenna with flexible beam control ability and radiation efficiency can well meet this goal.In this paper,a high gain beam steering antenna based on phase compensation and aperture field superposition principle is proposed.The main research contents are as follows:1.A multibeam switching antenna based on E-shaped metasurface is designed.In this paper,the phase control characteristics of metasurfaces on electromagnetic waves are studied.An E-shaped metasurface unit with 1-bit phase response is designed by using the current reversal effect.Based on the Generalized Laws of Reflection and Refraction,the metasurface is phase-coded to achieve a high-gain multibeam antenna.The results show that the antenna can realize the modulation of three and four beams in Ku band,the peak gain is 9.8d Bi,and the aperture efficiency is 9.3%,and the maximum beam pointing angle is（θ,ψ）=（0°,-67°）.2.A high gain beam steered antenna based onΦ-shaped metasurface is designed.Based on the multi-layer cascade and current reversal effect,aΦ-shaped high transmittance metasurface unit with a 180°phase difference is designed in this paper.Based on the comprehensive analysis of phase compensation and aperture field superposition principle,the calculation method of metasurface beam focusing is obtained.Then according to the clock signal output by the MCU,the PIN diode could be controlled in real time,and the single and multi-beam focusing would be realized.In order to further improve the gain and aperture efficiency of the designed antenna,there is a folded transmission array reflector based on the analysis of the polarization characteristics of theГ-shaped metasurface and the derivation of the ray tracing principle designed in this paper.The results show that the folded array antenna has a height of 0.28λ₀,and can realize multibeam steering and single/double beam scanning in Ku band.Tthe maximum beam pointing angle is（θ,ψ）=（0°,-67°）.After loading the reflector,the peak gain is 14.7d Bi and the aperture efficiency is 38.14%.