V.I. Kalinin - Ph. D. (Phys.-Math.), Senior Research Scientist, Head of Laboratory, Fryazino branch of Kotel\'nikov IRE of RAS. E-mail: val.kalinin@mail.ru D.E. Radchenko - Post-graduate Student, Kotel\'nikov IRE of RAS (Moscow). E-mail: dm.radchenko@gmail.com V.A. Cherepenin - Dr. Sc. (Phys.-Math.), Corresponding Member, Professor, Deputy Director, Head of Laboratory, Kotel\'nikov IRE of RAS (Moscow). E-mail: cher@cplire.ru