Gravity deformation of large reflector antennas causes deterioration of antenna performance.To solve the problem,a method of realtime adjustment of subreflector to reduce the influence of gravity deformation is proposed in the paper.The influence of the position translation and rotation of subreflector on antenna gain and pointing is an-alyzed.A mathematical model about the posture change of subreflector with the adjustment of antenna elevation an-gle is built.A set of data about the main reflector deformation of 35 m antenna for different elevation angles was ob-tained through digital photogrammetry.The best fit was conducted.Then,a set of optimum position coordinates of subreflector obtained through best fit were superposed with the measured displacement data of subreflector under the action of gravity with respect to different elevation angles.Next,a set of final adjustment data of subreflector was obtained and substituted into the mathematical model.The best fit was conducted again by using least squares to calculate parameters of the mathematical model.The model was used to adjust subreflector in realtime to reduce the influence of gravity deformation on antenna performance.Simulation results show that the gain of a 35 m antenna in X band and Ka band can be increased by 0.52 dB and 1.95 dB after subreflector position is adjusted in realtime by u-sing the model.
NETL
NSTL
维普
万方数据
