А.P. Trifonov - Dr.Sc. (Eng.), Professor, Head of Radiophysics Department, Honored Scientist of the Russian Federation, Voronezh State University. Е-mail: trifonov@phys.vsu.ru, trirad@mail.ru Yu.N. Pribytkov - Ph.D. (Phys.-Math.), Associate Professor, Assistant of Radiophysics Department, Vo-ronezh State University. Е-mail:ypribytkov@gmail.com