Monopulse broadband antenna

The directional patterns (DP) of antennas for the monopulse (MP) coordinate measurement method have complex, sometimes contradictory, requirements. For a survey station, for a number of reasons, some kind of compromise must be provided between the absolute signal level and the width of the linear area of the direction finding characteristic (DFC), which are determined by the level of suppression of neighboring monopulse DP. The purpose of the article is to consider the problems of constructing and describing a broadband antenna for a monopulse amplitude coordinate determination method for a survey radar station. In the process of analyzing existing technical solutions and developing new ones, the primary focus is on the level of intersection of monopulse patterns and its stability across the operating frequency band. It is demonstrated that the wideband performance of monopulse radiation patterns in a parabolic reflector antenna is limited by both the required intersection level and its stability. A numerical analysis of several technical solutions was conducted to enhance the stability of the intersection level. The article proposes a design for a reflector antenna feed system based on log-periodic radiators. In this design, the alignment of the phase centers of the radiators is achieved through their precise positioning, orientation, and the compact design of the radiators themselves. The results of modeling a parabolic reflector antenna using this feed system are presented. Through prototyping, the functionality of the design was confirmed, demonstrating stability in the radiation pattern intersection level within a range of 3 ± 1 dB across a frequency band of at least three octaves.