The Research Of High Performance Antenna Based On Metasurface

The antenna is a transducing device for converting current in circuits and space electromagnetic waves,and is also an important component of a wireless communication system.The rapid development of modern wireless communication technology has made the antenna system develop in the direction of high performance,versatility,intelligence,low cost and easy of integration.In recent years,research on electromagnetic metamaterials has received more and more attention.Metamaterials have some physical properties that not found in natural materials and can break through the electromagnetic properties of traditional materials.The replacement of three-dimensional metamaterials with two-dimensional surfaces,that is,metasurface(MTS),applied in antenna design,which can provide new ideas for the realization of high-performance antennas.Therefore,it has great scientific significance and broad research prospects.The paper mainly design high-performance antennas based on MTS.The main content of this thesis include:1.A dual-band high-gain antenna based on MTS was designed.Starting from a simple single-ring slot antenna with adjustable frequency band,the dual-band antenna design is realized by adding a ring-slot branch without changing the first frequency band.And then increasing a MTS to improve the antenna gain.The measured dual-band bandwidth is 22.44%and 11.71%,respectively,and the peak gains are 8.74 dBi and 9.53 dBi,respectively.2.A metasurface-based broadband antenna fed by an aperture coupling through a coplanar waveguide(CPW)was designed.The antenna design is starting from a conventional patch antenna fed by CPW with a coupling aperture at the end.Using a uniform MTS instead of a traditional patch as the radiating element can significantly improve the antenna's impedance bandwidth in low frequency band.Secondly,a non-uniform MTS is further adopted to adjust the couple between the MTS and the feed aperture.And then stepped impedance matching branched are added to the coupling aperture to improve the matching level of antenna in high frequency band.Finally,slightly reduce the size at the end of the coupling aperture to achieve a broadband antenna design with the bandwidth of 67.3%.The peak gain of the antenna is 9.18 dBi,and the gain is uniform over a wide frequency range.3.A broadband dual-polarized antenna based on metasurface was designed.The antenna design is starting from a single-polarized antenna fed by a microstrip line through an aperture,the use of a metasurface instead of a conventional patch as the radiating element facilitates broadband characteristics.Two sets of microstrip lines and coupling apertures are used to form two mutually perpendicular feeding circuits to realize dual polarization characteristics.In order to further increase the antenna bandwidth,the metasurface is rotated by 45°.At the same time,in order to prevent the deterioration of the radiation pattern,the metasurface is chamfered and the gap is loaded.The final designed broadband dual-polarized antenna has a two-port impedance bandwidth of more than 50%,peak gain of 9.36 dBi,and has a high isolation between two ports in the operating frequency band,less than-24dB.The high-performance antennas based on metasurface proposed in this paper are both high-performance,versatile,low-cost and simple in structure,which can provide high-quality antenna design solutions for indoor communication systems and broadband wireless communication.