| With the continuous advancement of deep space exploration activities,spaceborne antennas are developing in the direction of large diameter,high storage ratio,light weight,and high precision to meet the needs of multi-band,multi-purpose,and high-gain antennas.However,due to the impact of the harsh space environment,the structure of the spaceborne antenna will be deformed during service,which will lead to the deterioration of its electrical properties and eventually fail to work properly.So,this thesis takes a space-borne reflector antenna as the research object;and focuses on a series of key technologies such as the influence mechanism of the antenna structure deformation on the electrical performance,the change of the electrical performance during the antenna’s on-orbit operation,and the electrical performance compensation,including:1)Based on the theory of physical optics,the calculation formula of the electrical performance of the reflector antenna is deduced in detail,and the specific calculation process and method are given.Then the calculation program of the electrical performance of the reflector antenna is written with the help of MATLAB.Finally,taking a 17 m-diameter space-borne reflector antenna as an example,the calculation results are compared with the simulation results of FEKO to verify the correctness of the formula derivation and the program.2)The influence mechanism of the structural deformation of the reflector antenna on the electrical performance is studied.Firstly,the specific influence of the change of the phase distribution of the aperture field of the reflector antenna on the electrical performance is analyzed,and then the relationship model between the deformation error of the antenna structure and the electromagnetic field is further deduced based on the calculation formula of the electrical performance of the reflector antenna.The specific effects of attitude error and reflector deformation on electrical performance are analyzed respectively.Finally,the Taylor expansion of the phase error term caused by the surface deformation of the reflector is carried out,and the approximate calculation formula of the electrical performance of the deformed reflector antenna is obtained.The calculation example shows that the approximate formula can improve the calculation speed while ensuring the calculation accuracy.3)The thermal-induced deformation of the spaceborne reflector antenna during orbital operation and its influence on the electrical performance are analyzed.Firstly,the thermal analysis model of the antenna is established,and the temperature field of the antenna during the orbital operation is calculated by simulating the space thermal environment of the antenna during orbital operation.Then,the structural deformation of the antenna under the action of temperature load and the accuracy value of the reflector surface are calculated.The approximate calculation formula is used to calculate the electrical performance of the antenna structure after deformation,and the influence of the antenna structure deformation on the electrical performance and the worst case are found combined with the surface accuracy value.Finally,taking the worst case as an example,the least squares method is used to solve the optimal position and direction of the feed after the deformation of the reflector.And the electrical performance is compensated by adjusting the feed.The compensation results show that this method can effectively improve the effect of antenna structure deformation on the influence on electrical properties.4)Aiming at the problems of complicated operation and time-consuming calculation of the electrical performance of the reflector antenna by the existing electromagnetic simulation software,based on the research theory of this thesis,a software platform for the analysis of the electrical performance of the reflector antenna was developed by using C# language and MATLAB.The software platform realizes the functions of fast calculation and compensation of the electrical performance of the reflector antenna,and provides users with a practical,efficient and easy-to-operate interactive interface.The software platform is used to analyze a 3 m-diameter circularly symmetric reflector antenna,which verifies the practicability and reliability of the software platform. |
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