O.E. Glukhova − Dr.Sc. (Phys.-Math.), Professor, 

Head of Department of Radiotechnique and Electrodynamics, 

Saratov National Research State University named after N.G. Chernyshevsky

E-mail: glukhovaoe@info.sgu.ru 

M.M. Slepchenkov − Ph.D. (Phys.-Math.), Associate Professor,

Department of Radiotechnique and Electrodynamics, 

Saratov National Research State University named after N.G. Chernyshevsky 

E-mail: slepchenkovm@mail.ru