Research On Novel Antenna Technologies Based On Metasurface

With the development of the radio system,the demands for the antennas on aircrafts are growing rapidly.While the traditional means can no longer meet the requirements,novel technologies as metamaterials provide new solutions to the development of antennas by artificially manipulating the electromagnetic wave.Metasurface can be used to manipulate the electromagnetic wave with controlling its amplitude and phase.The applications of metasurface in novel antenna technology are studied from three aspects as beam control,surface wave suppression and polarization manipulation.The researches originate from fundamentals combined with actual application requirements,aiming to solve the existing shortages of the antennas and radomes.Firstly,the manipulation of reflection phase and radiation beam with gradient metasurface is studied.The high efficiency conversion of propagation wave to spoof Surface Plasmon Polaritons(SPPs)is achieved by the discrete gradient phase generated by units with different structural parameters.Meanwhile,the planar horn array is proposed as the quasi plane wave excitation to match with the field of the SPPs.And for the first time,the spoof SPP antenna realizes efficient radiation with ultra-low profile and high gain.This type of antenna has the characteristics of frequency scanning and stealth performance,and is easy to be conformally designed,which shows promising values in the antenna design on the aircraft platforms.Secondly,the suppression effect of the element structure with effective negative permeability on the surface wave is studied.Aiming at improving the anti-jamming performance of Beidou navigation antenna,the influence of mutual coupling on the anti-jamming performance is analyzed,and a design method of circular polarization antenna array with high isolation loaded with magnetic metamaterials is proposed.By analyzing the equivalent circuit of the Split Ring Resonator(SRR),the substrate integrated SRR with effective negative permeability is designed to reduce the mutual coupling between the antenna elements.More than 10dB enhancement of isolation is obtained and the performances of the antennas are improved at the same time.The hardware-in-the-loop simulation results show that the anti-jamming performance can be improved obviously by adding the substrate integrated SRRs.This design method is of great significance to further improve the anti-jamming performance of navigation antenna system.Finally,the manipulation of the polarization is studied.In order to improve the bandwidth of the transmissive polarization conversion surface,a novel configuration of the metasurface based on tightly coupled structures is proposed.The analysis of the influence on the transmission performance by varying the key parameters is stressed,and then the detailed design method is introduced.The proposed structure has low transmission loss(<1dB)and wide bandwidth(>70%)performances,and the Polarization Conversion Ratio(PCR)is higher than 97%.The equivalent circuit model is proposed and the mechanism for wideband is explained.The excellent characteristics of the structure are verified by the sample fabrication and measurement.This work provides a new solution for ultra-wideband transmission polarization converter.