A. O. Kasyanov - Dr.Sc. (Eng.), Deputy Head of Department of FSUE «Rostov-on-Don Research Radiocommunication Institute» FRPC. E-mail: kasao@mail.ru Yu. G. Popov - Head of Sector of FSUE «Rostov-on-Don Research Radiocommunication Institute» FRPC. E-mail: ayv2004@mail.ru

This paper has been devoted to study of the problem of superdirectivity mode implementation for the HF band receiving antenna arrays. The superdirectivity mode has been implemented using the criterion of signal-to-noise ratio (SNR) maximization with account of the gain-phase errors of exciting voltages at the antenna row, resulting in distortions of the array directivity diagram. The conditions of slight directivity distortions have been determined. The degree of directivity distortion has been characterized by the protection coefficient S. For the given values of S and level of gain-phase distribution errors it is possible to determine restrictions necessary to calculate the weighting coefficients according to the maximum SNR criterion. The relation between the degree of directivity distortion and the values of S has been presented. The effect of gain-phase errors on the shape of directivity diagram of antenna array in super-directivity mode has been studied numerically. The results of numeric simulations explicitly have demonstrated the possibility to use protection coefficient as an effective tool for control of directivity diagram distortions. It has been also shown that the decrease of distortions of directivity diagram of antenna array in super-directivity mode results in broadening of the main lobe.