An adjustment method for active reflector of large high-frequency antennas considering gain and boresight

Abstract

The design of the Qitai 110 m Radio Telescope (QTT) with large aperture and very high working frequency (115 GHz) was investigated in Xinjiang, China. The results lead to a main reflector with high surface precision and high pointing precision. In this paper, the properties of active surface adjustment in a deformed parabolic reflector antenna are analyzed. To assure the performance of large reflector antennas such as gain and boresight, which can be obtained by utilizing an electromechanical coupling model, and satisfy them simultaneously, research on active surface adjustment applied to a new parabolic reflector as target surface has been done. Based on the initial position of actuators and the relationship between adjustment points and target points, a novel mathematical model and a program thatdirectly calculates the movements of actuators have been developed for guiding the active surface adjustment of large reflector antennas. This adjustment method is applied to an 8 m reflector antenna, in which we only consider gravity deformation. The results show that this method is more efficient in adjusting the surface and improving the working performance.

Active Surface Compensation for Large Radio Telescope Antennas

“…In this context, the adjustment amount coupling of adjacent panels must be taken into account. To improve the beam pointing and antenna gain, the authors proposed an electromechanical coupling calculation method of the active surface adjustment amount [53] of large reflector antennas. This method first establishes and modifies the finite element model of the antenna structure and then determines the corresponding target surface through panel movement and fitting adjustment, overall reflector surface precision adjustment, as well as panel fitting, and rotation adjustment to calculate the best adjustment amount of the actuators quickly.…”

“…Each significant advancement in radio telescope antennas has been a milestone in the development of astronomy, without exception. As the most commonly used radio telescope antennas, reflector antennas [3,4] can easily implement a large aperture and narrow beam, with high resolution and high sensitivity; hence, they are widely used in the fields of radio astronomy, radar, communication, and space exploration [5,6]. In the past, the aperture of a large ground-based radio telescope antenna was usually greater than or equal to ten meters.…”

Preliminary study of regulation technology of wind field distribution on QTT site based on test of equivalent wind field

“…(3) 在天线外部修建一个 天线罩来隔绝外部环境因素对天线的影响 [14] , 虽然天 线罩对减小风荷载有很明显的作用, 但天线罩是天线 前面的障碍物, 对天线辐射波会产生吸收和反射, 改 变天线的自由空间能量分布 [15] , 并在一定程度上影响 表 1 AR866的主要性能参数表…”

Reconstruction of vibration-deformation-induced pointing error via optimized acceleration measurement points for large reflector antennas

“…Thus, the best-fitting paraboloid can be found. According to the best-fitting paraboloid theory 15 where ui, vi, and wi are location information of the i th measurement point in the UVW coordinate system.…”