The Analysis Of The Effect Of Structural Errors On Electrical Performances Of Reflector Antenna

Reflector antennas, which have the advantage of high gain and simple structure, are widely applied in some fields, such as communication, radar and radio astronomer. As a typical electromechanically-integrated product, the electrical performances will be affected by structure errors, especially the sidelobe. In order to analyze the electrical performances of antennas accurately and improve the level of the integrated design of antennas, the best way is to take the structural parameters into account during the analysis of electromagnetism. The relation between structural errors and electrical performances of antennas is obtained.This thesis makes analyses on the effect of the random error of the reflector on the electrical performances. The proper degree of discretization is obtained when there is random surface error, as well as the relation between the root mean square of normal surface error and the gain. Through the analysis of the effect of random surface error in different region of reflector on the pattern, it concludes that surface accuracy should be distributed to different regions according to requirements.The misalignment errors are classified into three axial directions of the space, and brings out a precise calculation method with which the effect of misalignment errors on the average power pattern can be analyzed. Through numerical simulation, the rule of the effect of each parameter on the pattern is obtained, and the expression is built which shows the relation between the rotation error of the reflector and the focal offset of the feed.The effect of length errors of hoop truss on the surface accuracy of reflector is researched based on the available model of Hoop Truss Deployable Antenna. A histogram is obtained, which shows the accuracy difference when each bar of the truss has a certain error and the effect of each bar on the surface accuracy. The analysis of the effect of weaves structure of mesh reflector on electrical performances is done. Weave structures of wiry mesh reflector is summarized. According to the reflector antenna, a pyramidal horn is designed, and models of three types of mesh reflector is built and applied on tow types of antenna. Far field gain pattern of reflector antenna is calculated by suitable methods. After analysis and comparison, a better weave structure is found. The research can provide useful suggestion on engineering practice.