High-Performance Antenna And Its Array Design Based On Artificial Electromagnetic Structure

Metasurface(MS)is a two-dimensional periodic artificial electromagnetic structure with sub-wavelength structure,which has unique electromagnetic characteristics and design flexibility.Research on the MS antennas in which the MS directly functions as a radiator has drawn more and more attention.The MS antenna has excellent performance of wide band and high gain while maintaining a low profile.But up to now,the reported MS antennas still have the disadvantages of large structure size and single polarization.To improve the radiation performance and reduce the size of the MS antenna,this paper innovatively introduces the high impedance surface(HIS)into the traditional MS antenna.A novel low-profile wideband hybrid metasurface(HMS)antenna and its antenna array with the adjacent elements sharing edge patches of the elements are presented and analyzed.Furthermore,a quad-polarization reconfigurable HMS antenna array is designed and analyzed based on the reconfigurable feeding network.Through the design of isolation structure and feeding network,a compact dual-polarized MS antenna array with wide band and high isolation is realized.These antennas and arrays have wide application prospects in modern wireless communication systems.The main research contents of the thesis are summarized as follows:In chapter 1,the research background of this thesis is presented.First,the research background of metamaterial-based antennas is introduced.Then,their development and research status are reviewed.Finally,the main work of this thesis is summarized.In chapter 2,the design theory and method of artificial electromagnetic structure are mainly introduced.In chapter 3,a novel low-profile wideband HMS antenna is designed based on the idea of integrating HIS and MS antenna.By integrating a one-dimensional grounded HIS,the antenna can suppress the surface waves propagating along the substrate,thus improving the radiation performance of the antenna.Furthermore,based on the antenna unit,a compact high-performance HMS antenna array is designed,where the adjacent elements share HIS,and the miniaturization of the array is realized while maintaining its wide bandwidth and good radiation performance.Simulation and measured results show that the antenna and array have good performance.In chapter 4,an HMS antenna array with quad-polarization reconfiguration is designed.Firstly,based on the design method and theory of HMS antenna,a radiation element that can be applied to the polarization reconfigurable antenna array is designed.Secondly,the existing realization technology of reconfigurable antenna array is analyzed,and a reconfigurable feeding network is designed.Finally,combined with the antenna array and the reconfigurable feeding network,an HMS antenna array with four polarization modes reconfigurable is realized.The impedance bandwidth of the polarization reconfigurable antenna array is maintained for all modes,and wide 3-dB axial ratio bandwidth for circular polarization modes is achieved.Simulation and measured results show that the antenna and array have good performance.In chapter 5,the realization technology of dual-polarized antenna array and the method to improve the isolation are studied,and a wideband dual-polarized MS antenna is designed,with low-profile is proposed,which can realize vertical and horizontal linear polarization with uniform radiation performance.Furthermore,based on the dual-polarized MS antenna element,two compact wideband antenna arrays with high gain and low cross-polarization are designed.Besides,a novel strip mushroom structure is designed and loaded between the array elements to improve the port isolation as well as reduce cross-polarization.Both the simulated and measured results show that the antenna and its array have good performance.Finally,in chapter 6,the research of this thesis is summarized,and the future research is prospected.