K.V. Mashinsky – Junior Research Scientist, 

Saratov Branch of Kotelnikov Institute of Radio Engineering and Electronics of RAS

E-mail: konstantin-m92@yandex.ru

V.V. Popov – Dr.Sc. (Phys.-Math.), Head of Laboratory, 

Saratov Branch of Kotelnikov Institute of Radio Engineering and Electronics of RAS

D.V. Fateev – Ph.D. (Phys.-Math.), Senior Research Scientist, 

Saratov Branch of Kotelnikov Institute of Radio Engineering and Electronics of RAS; Saratov State University