O.S. Litvinov, A.A.Giliazova, P.V. Rusakov, D.D. Ganzii

The estimation of the impact that single and grouped interferences have on the main lobe of a directional diagram of an adaptive antenna array is useful in the context of problems of spatial defence of radiochannel from interferences. In this article authors present the results of such estimation that was done using eigen diagram forming algorithm. The calculations were made for the situations of one, two or three interferences impacting the main lobe from different directions; the results are presented in tables and graphs. When the direction of incoming interferences moves closer to the axis of the main directional lobe the useful signal suppression coefficient increases. For example, when a single interference comes from the direction that forms 10 grad angle with the axis of the main directional lobe the signal suppression coefficient is 1.4 dB, while the same interference from the direction 2 grad makes it increase to anormous 24,7 dB. Authors also analize the impact of other parameters such as the power, of interferences, their degree of correlation, the angle distance between them, the quantity of interferences. The process of adaptation is shown on graphs. The characteristic parameters for groups of interferences are presented. The results of this work can be used to assess the impact of interferences on the main diagonal lobe of an adaptive antenna array within the current signal-jamming situation at the given location of the means of communication.