A.L. Khvalin - Dr. Sc. (Eng.), Associate Professor, Saratov State University named after N.G. Chernyshevsky. E-mail: khvalin63@mail.ru
L.L. Strakhova - Ph. D. (Phys.-Math.), Associate Professor, Saratov State University named after N.G. Chernyshevsky
A.V. Vorobiev - Engineer, NIKA-Microwave, Ltd (Saratov)