A. D. Vinogradov, P. A. Levashov, V. A. Mylnikov, E. N. Sazhin

The structure of a planar direction-finding antenna array with log-periodic dipole antenna of the normal (vertical) polariza-tion, ensuring a circular service area of radio direction finder is justified. The proved structure of an eighteen-elements flat antenna array with log-periodic dipole antennas of the vertical polarization consist of the six identical three-element non-uniformly-filled linear antenna subarrays, placed along the side of an equipotential hexagon. The results of mathematical simulation of directional patterns of antenna arrays, peak and phase the direction-finding characteristics, gained taking into account electrodynamic interaction between the log-periodic dipole antennas at fourfold overlap of the effective range of frequencies are given. The three-step procedure of forming the direction-finding characte-ristics with small, not exceeding 0,2 deg., errors of direction finding, limited by interdependence of log-periodic dipole an-tennas is developеd. The article includes 9 drawings and references to 14 sources of information.