a St. Petersburg State Electrotechnical University ETU “LETI,” St. Petersburg, Russia
b Mokerov Institute of Ultra High Frequency Semiconductor Electronics, Russian Academy of Sciences, Moscow, 117105 Russia
Correspondence to: *e-mail: p.p.maltsev@mail.ru
Received 23 September, 2021
DOI: 10.1134/S2635167622070138