K.V. Mashinskiy - Post-graduate Student, Saratov State Univercity named after N.G. Chernyshevskiy E-mail: konstantin-m92@yandex.ru D.V. Fateev - Ph.D. (Phys.-Math.), Senior Researc Scientist, Kotelnikov Institute of Radio Engineering and Electronics (Saratov Branch) V.V. Popov - Dr.Sc. (Phys.-Math.), Head of Laboratory, Kotelnikov Institute of Radio Engineering and Electronics (Saratov Branch); Professor, Saratov State University named after N.G. Chernyshevskiy

E.E. Kozlova1, A.R Safin2, S.A. Nikitov3

1-3 Kotelnikov IRE of RAS (Moscow, Russia)