The Design And Optimization Of Large-size Broadband Antennas

Large-size broadband transmitting antenna is one of the important components of medium and long-wave and short-wave communication systems and radar systems,and has many applications in modern military communications,electronic countermeasures,space exploration,space communications and other fields,such as the 500-meter dipole broadband antenna of the RPI payload on the American IMAGE satellite,the 70-meter dipole broadband antenna of the DSX satellite WPIx,and the 10-meter dipole broadband antenna of the Mars Express MARSIS payload.In addition,in the military,VLF and low-frequency submarine communications,broadband electronic countermeasures in short-wave bands and other large-size broadband antennas are also widely used.Therefore,large-size broadband antennas are one of the scientific and technological fields in which the world’s military powers and aerospace powers compete fiercely.With the vigorous development of China’s aerospace technology,space-based large-size broadband transmitting antenna technology has become the "rigid demand" for the development of China’s aerospace engineering and space exploration technology.In addition,with the heating up of the world situation in recent years,new requirements have been put forward for land-based large-size broadband antennas.In this study,CST software was used to study the problem that the arms of the antenna were not collinear after the large-size flexible dipole antenna on the triaxial stable satellite platform was deployed,and the electrical performance of the non-collinear dipole broadband transmitting antenna was modeled and simulated,and compared with the collinear dipole antenna of the same size,and the measured experiment based on the scaled antenna was carried out on the basis of the simulation experiment,and the simulation results were verified.The results show that the impact of two-arm non-collinear on antenna performance can be improved by matching networks,etc.In addition,in this study,a theoretical model of the ground test system of space-based large-size dipole antenna is also established,on this basis,the wind impedance,ground network design,and weight reduction of the ground test system are simulated and tested,and experiments are carried out to verify the simulation results,and the results show that the influence of wind offset on the antenna is negligible when the offset is not much.The ground network should choose an improved ground network.The hollowing out option is feasible.In addition,a numerical model of cage antenna is established,the structure of cage antenna oscillators commonly used in land-based large-size broadband transmitting antennas is optimized,and three optimization directions are proposed for the design of future broadband cage antennas.