Design of a Control System of Compensation for the Focal Displacement of Feed of a 50m Antenna

This paper fits curves of axial displacement of focal point of an X-band feed at different elevations angles for the 50m antenna in the Miyun District of Beijing.The displacements are due to gravitational deformations of the antenna.In order to compensate the axial displacement, this paper designs a feed control system including a current loop, a speed loop, and a position loop.Simulations of the system are carried out based on the Matlab/Simulink software.The results show that the system can compensate the axial displacement of focal point and has satisfactory performance under dynamic or static condition.