| With the advent of the 5G era and the development of communication technology,human beings have higher and higher requirements for electromagnetic wave transmission,especially in the field of satellite communication,antenna technology and military.The polarization state of electromagnetic wave is an important performance.To realize the regulation of electromagnetic wave propagation,it is necessary to regulate the polarization state of electromagnetic wave.Therefore,whether in the military field or in the field of modern communication in the face of complex application environments,how to efficiently and conveniently regulate the polarization state of electromagnetic waves is very important.The appearance of metasurfaces has improved people ’s ability to regulate electromagnetic waves.At the same time,it also has the advantages of thin thickness,low loss and easy fabrication.In view of the above problems,the performance and application of the designed polarization conversion metasurfaces in regulating electromagnetic polarization state are discussed in detail in this paper.The main research contents of this paper include:(1)An ultra-thin circularly polarized transmission-type polarization conversion metasurface unit is designed to control circularly polarized electromagnetic waves.When the circularly polarized electromagnetic wave is incident,the unit only uses a single-layer substrate structure(thickness of 0.06 operating wavelengths)to achieve a cross-polarization transmission amplitude higher than 0.97.The metasurface unit is based on the Pancharatnam-Berry phase principle,which is characterized by the precise control of the phase by rotating the unit structure while keeping the transmission amplitude unchanged.(2)A high-gain metasurface lens antenna is designed,and the designed ultra-thin and efficient metasurface is applied to the antenna.A metasurface array with improved gain is designed and integrated with a circularly polarized microstrip antenna to form a metasurface lens antenna.The results show that the gain of the metasurface lens antenna is improved at the working frequency of 12 GHz.Secondly,an antenna with orbital angular momentum(OAM)vortex beam is designed,which can realize the multi-mode control the OAM beam.(3)A low radar cross section(RCS)metasurface array antenna based on ultra-wideband reflective polarization conversion metasurface is proposed.Firstly,the designed polarization conversion metasurface unit structure uses two pairs of L-shaped metal strips and an air layer is added between the metal plate and the dielectric layer,which can achieve polarization conversion in the ultra-wideband range.Secondly,the unit is arrayed according to the checkerboard,and it is integrated with the microstrip array antenna to form a low RCS metasurface array antenna.The simulation results show that compared with the reference antenna,the low RCS metasurface array antenna not only has good RCS reduction in the broadband field,but also can realize complex beamforming,such as flat-top beam. |
PDF Full Text Request