Analysis Of High-efficiency Planar Array Antenna

With the rapid development of science and technology and in order to deliver large-capacity images,voices,and data information in real time,the fast data rates of communication system are increasingly demanded.At this high data rate requirement,the broadband,high efficiency,low profile and higher frequency antennas have great application prospects.The research of this thesis is mainly aimed at the design of high-efficiency planar array antenna in the form of waveguide.The research content is divided into four parts,and the design of four types of antennas is expounded.The main research is as follows:1.A 64-element dual-polarization high-efficiency low side-lobe planar array antenna working in the Ku-band is studied and designed.The antenna unit adopts a step transition square horn antenna that is loaded with a cross metal grid structure on the radiating surface.The dual polarization of the antenna is achieved by the Ortho-Mode Transducer.The amplitude of the array elements is fed by taking amplitude taper to realize low side-lobe.Finally,the efficiency of array is greater than 84.4%in the frequency band,and the relative side-lobe level is less than-18.03dB.2.Combining quasi-TEM wave and CTS antenna,this thesis studied and designed a high efficiency and low profile series-fed CTS array antenna working in the millimeter wave band.In order to solve the antenna grating problem,two design schemes are given.First,the type of series-parallel connection,by introducing the branch structure at the coupling slot of CTS antenna to realize the energy is equally divided into the narrow radiation slot to form a 1×2 sub-array;Second,the type of Capacitive-loaded,shortening the waveguide wavelength by loading a capacitive corrugated slow-wave structure at the bottom end of the parallel-plate waveguide.Finally,both the two design schemes of array antennas achieve the profile height of less than 1.3?₀ and the efficiency of more than 76%.3.A wide-band,high-efficiency and low-profile 64-elements H-plane parallel-feeding array based on the gap waveguide technology working in the millimeter-wave band is studied and designed.The antenna unit adopts a cavity-coupled slot antenna.By adding a layer of cavity,the difficulty of the feed network design is reduced,and the bandwidth of the antenna is broadened by loading a matching step in the cavity layer.Finally,the antenna designed has a profile height of 1.31?₀,achieving the impedance bandwidth of 23.3%and the antenna efficiency of more than 80%in the working band.4.A wide-band high-efficiency 64-elements circularly polarized array antenna working in the millimeter-wave band is studied and designed.The antenna unit adopts a cavity-coupled slot antenna and loads a septum polarizer on the radiating surface to realize circular polarization.The designed circularly polarized antenna array has a profile height of 2.67?₀,achieving the impedance bandwidth of 25.6%,the 3 dB axial ratio bandwidth of21.3%and the antenna efficiency of greater than 90%in the working band.