A.A. Shvachko - Post-graduate Student, Yuri Gagarin State Technical University of Saratov E-mail: alexandr1899@gmail.com A.A. Zaharov - Dr. Sc. (Eng.), Professor, Head of Department «Electronic Devises and Equipment», Yuri Gagarin State Technical University of Saratov E-mail: zaharov@sstu.ru I.N. Afonin - Post-graduate Student, Yuri Gagarin State Technical University of Saratov E-mail: pi_3.141@mail.ru Ya.V. Turkin - Post-graduate Student, Yuri Gagarin State Technical University of Saratov E-mail: turkin.yaroslav@gmail.com