D.V. Nefedov - Ph.D. (Eng.), Researcher, Saratov branch of the Kotel-nikov Institute of Radio Engineering, and Electronics Russian Academy of Sciences. E-mail: nefedov_dv@rambler.ru
S.Y. Suzdaltsev - Ph.D. (Eng.), Senior Researcher, Saratov branch of the Kotel-nikov Institute of Radio Engineering, and Electronics Russian Academy of Sciences