V.A. Permyakov - Dr.Sc. (Phys.-Math.), Professor, Department Antenna Devise and Propagation Radio Waves, National Research University «MPEI». E-mail: valerypermyakov@yandex.ru
M.S. Mikhailov - Post-graduate Student, Department Antenna Devise and Propagation Radio Waves, National Research University «MPEI». E-mail: mihailovms@mail.ru

The method of calculating the energetic characteristics of the phased array antenna above the flat earth surface is declared. Phased array antenna is a periodic system of unidirectional radiating elements (dipoles above the screen, Huygens' element) centers lie in one plane. Radiation pattern of a radiating element as a part of phased array is considered of known and is weakly directional. Model of an earth surface is considered of homogeneous half-space with losses. Accounting of the influence of an earth surface on radiating element of phased array is carried out by well-known formulas of wave interference. Then fields of all radiating element are summarized and a density of a flow of capacity in the intermediate and distant zones of phased array are calculated. The offered technique is applied to calculation of a sanitary-protective zone and a zone of restriction of phased array.