Petrov A. S., Pechurin V. A., Tegel S. A.

The article describes a switching circuit to generate a direction finding performance of 4-beam monopulse antenna system (MAS) of UAV ground control station where one Rx channel is used for generation of sum and two differential (azimuth and elevation) signals defining the target deviation from radar boresight. The use of this circuit allows not only the number of receivers to be reduced (one instead of three), but also the solution of separate channels phasing to be simplified. The calculation ratios have been obtained and using a computer they make it possible to evaluate the monopulse antenna system parameters at the system engineering level. These evaluations are to be made at the stage of product definition for the antenna system design with the issue of requirements imposed to separate AFD components. Besides, in adjustment and in case of faults occurring in operating equipment, the specific direction finding distortions can show the reason of their occurrence. There are given the analysis results of MAS direction finding performance at antenna system element parameters deviation (power combiner-dividers and phase shifting devices) from their ideal values. The phenomenon of MAS direction finding performance axes twisting and its zero drift from radar boresight is demonstrated.