L.I. Yusupova – Student, 

Department «Radio Engineering, Opto- and Nanoelectronics», Ulyanovsk State Technical University E-mail: lesanusupova@gmail.com

O.V. Ivanov – Dr.Sc.(Phys.-Math.),

Department «Radio Engineering, Opto- and Nanoelectronics», Ulyanovsk State Technical University Ulyanovsk Branch of Kotel’nikov Institute of Radio Engineering and Electronics of RAS E-mail: olegivvit@yandex.ru

M.A. Abelmas1, O.V. Ivanov2

1 Ulyanovsk State Technical University (Ulyanovsk, Russia)

2 Ulyanovsk Branch of the V.A. Kotelnikov Institute of Radio Engineering and Electronics of the RAS (Ulyanovsk, Russia)

1 abelmax1998@mail.ru; 2 olegivvit@yandex.ru