A.P. Trifonov - Honored Scientist of RF, Dr. Sc. (Eng.), Professor, Head of Department of Radiophysics, Voronezh State University E-mail: trifonov@phys.vsu.ru V.N. Vereschagin - Post-graduate Student, Department of Radiophysics, Voronezh State University E-mail: Slawa-W@mail.ru V.K. Marshakov - Ph. D. (Phys.-Math.), Associate Professor, Department of Radiophysics, Voronezh State University E-mail: mvk@phys.vsu.ru