Research On Optimization Design Method Of Arc Array Imaging Antenna

Airborne millimeter-wave arc array imaging radar is a new microwave imaging system for all-weather wide-area observation,which can realize omni-directional,large-field of view,high spatial and temporal resolution imaging observation.Arc array imaging antenna is the most important part of the whole system.Compared with the traditional linear array antenna,it has the advantages of multi-phase center,large aperture and wide scanning Angle,etc.which provides possibility to better meet the development needs of application,such as helicopters in static scene terrain avoidance,moving target trajectory tracking and searching,Synthetic Aperture Radar(SAR)imaging and so on.In this thesis,around the aspects of theoretical numerical analysis,antenna radiation pattern analysis,error analysis,array beam scanning method and optimization,low sidelobe antenna performance about the arc array imaging antenna has carried on the related theory research,and then computer co-simulation analysis experiment,through the simulation results verify the feasibility and effectiveness of the design method.The accurate numerical analysis,electromagnetic simulation analysis and error analysis of arc array imaging antenna were studied.Based on linear array analysis theory and array approximation theory,combined with the complex structure characteristics and working frequency of arc antenna,antenna radiation pattern simulation analysis has been carried out according to the derived arc antenna array factor.The script design method of API for complex model based on arc array imaging antenna has been proposed,then the numerical solution,simulation analysis and data post-processing were carried out.According to the influence of the grating lobe on array elements spacing,the amplitude error,phase error and assembly error have been analyzed under the condition of uniform Angle array element distribution,furthermore antenna radiation pattern error was simulated.Meanwhile the characteristics of antenna beam width,first side lobe and largest side lobe in the far region were studied.The omni-directional large-angle beam scanning,optimized antenna design,and low sidelobe antenna performance have been studied.A beam scanning control method based on arc array imaging antenna was proposed.The phase configuration,reasonable setup of feed network and power division network,selection strategy of effective radiation array element were studied.An optimization design method for azimuth-oriented beam scanning based on equivalent linear array method,virtual array element method and frequency scanning method has been proposed.Furthermore,the antenna radiation pattern was simulated and analyzed during beam scanning.Then,the method of mixed weighting of amplitude and phase of low-sidelobe antenna was carried out,and a distortion function distributed along the antenna aperture was introduced,after that,relation curves of antenna beam scanning Angle,beam bandwidth and sidelobe performance were obtained by using different amplitude Windows,which can provide reference for planning the distribution of amplitude-phase excitation and the reasonable selection of array elements spacing.