| Due to its anti-multipath fading and dual-polarization working modes,dualpolarization array antenna can improve frequency band utilization,increase communication capacity,enhance target detection and perception and information acquisition ability.It has incomparable advantages in many fields such as base station communication,meteorological detection,radar target detection and recognition in modern wireless field.It is one of the research hotspots in antenna field in recent years.The working stability of dual polarization antenna is directly proportional to the isolation between ports.Excellent port isolation can effectively suppress local selfdisturbance signals,which is the focus and difficulty of designing dual polarization antenna.At the same time,the dual polarization array antenna has twice as many ports as the single polarization array antenna.In addition to the antenna array,the antenna also involves a large number of microwave devices and connecting cables.Under the demand of pursuing miniaturization of the array,the electromagnetic interference of the actual array antenna has become a problem that can not be ignored.It is necessary to study and analyze its electromagnetic compatibility performance.Under this background,this paper mainly carries out the research work of high isolation dual polarization array antenna design and sidelobe optimization,electromagnetic coupling response calculation of array antenna and electromagnetic compatibility simulation analysis.1.Aiming at the poor isolation of dual polarization microstrip antenna,an orthogonal non-parallel-coupling feed antenna is designed to realize the port isolation of the antenna up to-42 d B in the working frequency band.The distribution of electric field intensity during antenna operation is analyzed,and the principle of improving isolation is expounded.The impedance matching state of the antenna is improved by loading sawtooth copper circumference around the antenna.At the same time,the beam width of the unit antenna is effectively expanded with the help of its kind of deflector.2.Based on the optimized unit antenna,a 1×8 and 8×8 linear array antenna are designed respectively.The sidelobe of the array antenna is optimized by using the unequal amplitude and in-phase excitation mode of Taylor synthesis method.The sidelobe level of the array antenna is reduced by about 7d B,the simulation is-20 d B left and right,and the measured optimal sidelobe level is-18.52 d B;The mechanical structure and polarization conversion circuit of the antenna are designed,so that the polarization state of the antenna can realize one key conversion,and then the antenna is processed,assembled and measured.The measured data of microwave anechoic chamber are in good agreement with the simulation results,which verifies the effectiveness of the design.3.In order to solve the problem of solving the electromagnetic coupling response of array antenna,based on the electromagnetic topology theory,the array antenna system is topologically decomposed,and the sub topology diagram and the simplified signal flow diagram based on practice are established.For different sub topologies,the transfer relationship of electromagnetic interaction between inner and outer layers is obtained based on the coupling path between them.Combined with the numerical analysis method,the electromagnetic coupling between different sub topologies is analyzed,and the coupling response method of corresponding components is given in theory;The three-dimensional electromagnetic simulation software is used to simulate and solve the electromagnetic interference and electromagnetic compatibility problems between antenna elements,antenna array surface and back cables,antenna system and external interference. |
PDF Full Text Request