Research On A Hybrid Metasurface High Gain Circular-Polarized Plate Beam Modulation Antenna

In recent years,with the development of satellite reception and mobile communication,the performance of antenna is more and more demanding.In wireless communication system and radar detection,it is necessary to ensure not only the high gain of the antenna,but also the cost of the antenna and the fast scanning of the beam.Parabolic antenna and phased array antenna promote the development of high-gain beam scanning,but the scanning process of parabolic antenna is slow,and the processing cost of phased array antenna is high when the feed loss of millimeter wave band is large and the number of array element is too large.Based on the Near-Field Meta-Steering（NFMS）method,this thesis focuses on the design of beam scanning array antenna with high gain,low cost and low loss by using metasurface to control electromagnetic wavefront.The main research contents and achievements are as follows:1.A high gain beam scanning antenna based on hybrid metasurface is designed.A hybrid metasurface is a metasurface composed of multiple functions or different elements.Firstly,the steps of antenna design using NFMS method are summarized.Secondly,a focusing-beam deflection metasurface antenna is designed based on phase compensation and focusing principle.Finally,on the basis of adding a metasurface in the center frequency（12 GHz）is realized±40°beam scanning,and gain loss during the process of scanning below 2.4d Bi.2.A high gain circular polarization beam scanning antenna with transmitting metasurface is designed.The traditional Concentric Array-Radial Line Slot Antenna（CA-RLSA）and two of the same phase gradient metasurfaces,which rotating antenna can realize±39°beam scanning,simulation results are in good agreement with test results.3.A high gain and low cost circular polarized beam scanning antenna is designed.Firstly,the theory of beam-tilted RLSA is introduced,and two kinds of RLSAs with different tilt angles are designed.Finally,compared with traditional NFMS system,need to use a metasurface beam scanning can achieve high gain,antenna can achieve scan angle for±31°,the overall height is 1.32₀of antenna.The simulation results are in good agreement with the test results.4.Combined with the principle of Orbital Angular Momentum（OAM）,this thesis puts forward a five modal OAM radial line slot antenna,implements the L=-1,±2,±3five modes of any transformation.Based on the unique electromagnetic characteristics of the metasurface,a 3-bit quantized encoding OAM antenna is designed.Two OAM antennas are designed according to the encoding scheme,and the effectiveness of the encoding scheme is verified by simulation.