THE IMPACT OF ANTENNA REFLECTOR DEFORMATION ON DIRECTION DIAGRAM
Background. The objects of study are the radiation patterns of parabolic antennas. Parabolic antennas are widely used in the passive direction finding problem. The monopulse method is one of the most common methods of passive direction finding. It requires accurate knowledge of the shape and orientation of the multi-beam antenna pattern. Space antenna systems are characterized by periodic changes in the shape of the reflector due to uneven heating, which leads to the distortion of the antenna radiation pattern. In many cases the displacement of individual points of the antenna reflector can be measured with high accuracy and approximated by surface representing a model of deformed reflector. However, the complete recalculation of the multipath radiation pattern is a computationally complex task. The main purpose of the article is to increase the computational efficiency of determining the parameters of the antenna directional pattern, considering the reflector deformation. Materials and methods. The results were obtained by computer simulation based on the calculation of radiation patterns using the brilliant point method. The article focuses on considering the linear deformation of the reflector in two adjacent quadrants and complex deformation, which consists of several simple deformations. Results. The computational efficient method of radiation pattern parameters evaluating was proposed and investigated. The applicability of the proposed method is shown. Conclusions. The effect of small deformations of the antenna reflector in arbitrary directions can be considered as a superposition of deformations in mutually perpendicular directions. This allows to estimate the displacement of the electric axis and the change of the main lobe width considering deformation along an arbitrary direction without recalculating the radiation pattern.