| Shaped reflector antennas have been widely used in satellite communications,satellite earth stations,monopulse radar and radio astronomy systems.With the development of shaped reflector antenna with large aperture,high frequency and low side lobe,it is necessary to design antenna structure with higher precision.It is necessary to find out the main structural factors that affect the electrical performance by electromechanical coupling of shaped reflector antenna,to design the structure precision requirement to meet the actual demand,and then to reduce the cost of design and manufacture,so that the electrical performance of reflector antenna can be optimized.Thus,it provides theoretical help and technical guidance for the design and manufacture of reflector antenna.(1)The structural factors affecting the electrical performance of shaped reflector antennas include random errors and systematic errors,all of which will lead to the deformation of the reflector.The position of the feed source relative to the reflector changes because of the deformation of the reflector.This will result in reflector error and feed error.The coupling relationship between displacement field and electromagnetic field of shaped reflector antenna is analyzed,and the physical optics method is applied to analyze the coupling relationship between the displacement field and electromagnetic field of shaped reflector antenna.The electromechanical coupling model of shaped reflector antenna is established and programmed by Matlab.The model is verified by 8m shaped reflector antenna and the correctness of the model is proved.(2)In this paper,the equivalent feed center of double reflector antenna is studied firstly,then geometric optics method is used as theoretical support,and the shape equation is established by satisfying the law of reflection and conservation of energy.Finally,the equivalent combined center of the antenna feed is determined according to the shape equation.(3)Based on the established electromechanical coupling model,the influence of gravity and wind load on the electrical performance of QTT shaped dual reflector antenna is analyzed,and the first side lobe level of the antenna before and after deformation under different working conditions is compared and analyzed.The importance and necessity of electromechanical coupling of antenna are obtained from the calculation results of half power lobe width and other electrical properties.(4)In order to calculate the electrical performance of shaped reflector antenna quickly,a electromechanical coupling analysis software of shaped double reflector antenna is designed based on C Builder.The software can be used to calculate the electrical performance and gain of shaped reflector antenna.The variation of side lobe level and the application of the software to the QTT shaped dual reflector antenna are proved to be effective. |
PDF Full Text Request