Research On Staring Beamforming Technology Of Spaceborne Phased Array

With the growth of 5G's commercial and user traffic,there are few remaining low frequency band spectrum resources that have been developed and utilized.For high frequency band spectrum resources,especially the Ka band that can be applied to satellite communications.This make it became the research focus of institutions,satellite communication is one of the important communication technologies.The traditional fixed beam scheme has a non-adjustable beam pointing,and the single beam serves the target area for a short time.It requires ntra-satellite beam switching,however,staring beam can change the beam pointing by updating the array weight of the phased array,it can extend the service time of a single beam to the target area,and does not require intra-satellite beam switching,so the staring beam is mainly used to provide continuous Service for area in need.In the first part of this paper,Firstly,the advantages and disadvantages of the three rapid beamforming algorithms are analyzed.Finally,the digital deploy phase method is selected as the staring beamforming algorithm;For higher side lobe issues,consider the formation factor and use the round caliber Taylor amplitude weighting method to reduce the side lobes.For the difference between main side lobe ratio and the expected value are large,the formation is improved to finally make the main side lobe ratio close to the expected value;Simulation analysis of the multi-beam situation,finally achieved multi-beam low side lobe beamforming.The second part mainly studies the gaze of the single target area.Firstly,the calculation model of the relative positional relationship between the satellite and the target is established.the next step is to control the degree of beam ellipse during the gaze.,Set the judgment conditions to control,in order to determine the gaze threshold of the judgment conditions,The gaze range,the minimum elevation angle of satellite coverage,the gaze time and the worst-case beam elliptical eccentricity of the two types of targets were simulated and analyzed for the gaze threshold.By comprehensive analysising finally determined a suitable threshold;the calculation and analysis compare the gaze beam scheme with the traditional fixed beam scheme.The results show that the gaze beam can extend the service time of a single beam to the target,and does not require frequent intra-satellite beam switching,which has obvious advantages.The two types of targets were simulated and analyzed,and the coverage of the 3d B beam range to the target area was observed and analyzed to finally control the degree of beam ellipse during the gaze process.Finally,for multi-target area gaze,firstly,for two types of targets,the semi-major axis and semi-minor axis length of the range of the 3d B beam during gaze is calculated to determine the effective radius of the beam;next,a multi-target area gaze algorithm is proposed,and finally achieve the gaze of multiple targets.Next,the coverage of the target within the range of 3d B of the beam during the gaze process is observed and analyzed.Finally,the effective coverage of the beam to the target at these moments and the average effective coverage is calculated for all moments.The simulation results show that the In the case of relatively dense target distribution,the gaze algorithm can effectively cover more than 95% of the targets.