Research on electromechanical field coupling model and solution strategy of large reflector antennas

Abstract

The overriding design goal of reflector antennas is accomplishing an acceptable electromagnetic performance. However, the success of this goal lies ─ for a substantial part ─ in the construction of mechanical structure, which ensures and restricts the achievement of its electrical properties simultaneously. The reflector antenna is a system that combines electromagnetic fields with structural deformation fields, in which electromechanical coupling problems exist. The high precision expected makes the coupling phenomenon more serious as reflector antennas develop towards a situation of large diameter and high band. Therefore it is necessary to do some research about the electromechanical coupling problems, establish precise field coupling model and get the solution strategies. This paper presents a electromechanical field coupling model based on the method of surface current. The model includes the systematic error, with considering all-around displacement of each node, based on which the interior surface deformation of elements could be got by the interpolation with shape function. The vertex normals of distorted curve are then applied to the surface current density to investigate its impact on the far-field electrical performance. The investigation of the coupling model and solution strategy led to an improvement of design level and to a better performance of reflector antennas.