Design Of The Low-RCS Antenna Based On Metasurface

With the rapid development of the detection technology,detecting enemy targets and hiding our own weaponry effectively has become a crucial issue in modern warfare.In the radar and communication system,the primary function of antenna is to radiate and receive electromagnetic energy effectively,antennas are always the great contributor for radar cross section(RCS).As a result,reducing the radar cross section of antennas and maintaining their radiation characteristics simultaneously has always been a focus of research in recent years.Metasurface,as the two-dimensional metamaterial,has ability that can control the amplitude,phase and the polarization of the electromagnetic waves freely and effectively.Furthermore,due to its features of easy fabrication,low cost and low-profile,metasurface can be integrated with antenna easily.So metasurface receives extensive attentions in the field of antenna stealth.In this thesis,several low-RCS antennas is proposed,and the research contents are shown as follows:The phase regulation capacity of the metasurface is used to design a chessboard surface.It can reduce the RCS when the structure is arranged around a slot antenna,and the radiation of the antenna can be guaranteed.Two novel polarization conversion metasurfaces with ultra-wideband and high polarization conversion ratio are proposed.By utilizing the theory of destructive interference,these unit cells are arranged around the patch antenna or slot antenna with chessboard structure respectively.The proposed four low-RCS antennas all show good RCS reduction ability,and the backward scattering of the antennas can be reduced at least 10 dB in the broadband.The radiation of the antennas also shows good performance at the same time.One of the four antennas is fabricated and measured,the results show well stealth characteristic,and it agrees with the simulation results.Based on the theory of F-P resonant cavity,two novel shared aperture metasurfaces(SA-MS)are proposed to reduce the RCS and improve the gain of the patch antenna.The simulation results show that the proposed antennas have characteristic of low-RCS,and the radiation performance is satisfactory.