K.R. Asanov - Master Student, Department «Radiotechnique and Electrodynamics», Saratov State University named after N.G. Chernyshevsky O.E. Glukhova - Dr.Sc. (Phys.-Math.), Professor, Head of Department «Radiotechnique and Electrodynamics», Saratov State University named after N.G. Chernyshevsky E-mail: graphene@yandex.ru